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Cesare FANTUZZI
Professore Ordinario
Dipartimento di Scienze e Metodi dell'Ingegneria
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Pubblicazioni
- Integrated Packaging system architecture
[Brevetto]
Donati, Claudio; Tacconi, Lorenzo; Fantuzzi, Cesare; Faglioni, Stefano
abstract
A Packaging System (PS) including: a Packaging Line (PL) comprising a Filling Machine (FM) and one or more Distribution Equipments (DE) connected via Conveyors, the Filling Machine and each Distribution Equipment including an electronic control system designed to store and execute software modules; a Line Controller (LC) programmed to manage configuration, communication and control of the Packaging Line, the Line Controller including a display, a keyboard, and a processing system designed to store and execute software applications configured to cooperate with the software modules in the Filling Machine and Distribution Equipments; a common overhead Message Display designed to provide basic visual information on the operation of the Filling Machine and the Distribution Equipments; and a Communication Network designed to connect the Line Controller to the Filling Machine, the Distribution Equipments, and the Message Display; wherein the software applications in the Line Controller include: a Line Configurator, which is a supportive "plug and play" tool designed to reduce and secure effective Packaging Line installation, start up and tuning at the manufacturing floor; a Line Commander, which is a master controller tool designed to optimize Packaging Line performance and product flows during production; a Recipe Manager, which is a management tool designed to accommodate production flexibility by improving "easy to use" Packaging Line resources and material; and a Conveyor Optimizer, which is a tool designed to optimize product transportation along the Conveyors.
2022
- Self-configuring BLE deep sleep network for fault tolerant WSN
[Relazione in Atti di Convegno]
Rosati, C. A.; Cervo, A.; Bertoli, A.; Santacaterina, M.; Battilani, N.; Fantuzzi, C.
abstract
This paper is focused on Wireless Sensor Network (WSN) leveraging on Bluetooth Low Energy (BLE) connectivity for low energy applications which is fault tolerant versus communication path failures. The topic is important to create a robust sensorized environment to be applied in industrial context or smart infrastructure to enable scheduled monitoring with low power consumption applications. Currently BLE applications are mainly thought for smart home solutions, health care and positioning systems. In those applications the BLE nodes are continuously supplied by external power suppliers. Our goal is to design a self-configuring network with a synchronized deep sleep behavior, aimed to optimize the energy consumption, with an overall active time interval constraint optimized with a data-driven method. The aim is to find a tradeoff between the on time and the ability to collect all the nodes data, pursuing a low power consumption. Our research is based on BLE protocols, interaction between edge systems for data collection and cloud system for data analysis and software agent optimization system. The paper analyses different configurations and describes the possible optimization algorithm to be used for the software agent design, in order to reach a fine-tuned control to improve the fault tolerance and fault diagnosis of the system. Finally experimental results are compared with the estimates obtained via a software simulation tool implemented for this architectural pattern.
2021
- A User Study for the Evaluation of Adaptive Interaction Systems for Inclusive Industrial Workplaces
[Articolo su rivista]
Villani, V.; Sabattini, L.; Zanelli, G.; Callegati, E.; Bezzi, B.; Baranska, P.; Mockallo, Z.; Zolnierczyk-Zreda, D.; Czerniak, J. N.; Nitsch, V.; Mertens, A.; Fantuzzi, C.
abstract
In recent years, production systems have become highly sophisticated and complex. As a result, while on the one hand, the least-skilled labor has been partially displaced by machines, high-skilled labor is more required to supervise and control advanced automation systems. In many cases, the complexity of machines implies an increased complexity of human-machine interfaces (HMIs), which are the main point of contact between the operator and the machine. To enable effective use of HMIs and to enable their usage by workers with different knowledge and capabilities, novel design approaches have been proposed. In particular, in this article, we consider the approach developed in the framework of the European research project INCLUSIVE, which aimed at designing industrial HMIs that adapt to the skills and capabilities of human operators. As a case study, we consider an adaptive interaction system for the woodworking industry and present an extensive evaluation carried out in real production environment with shopfloor workers. The effectiveness of the INCLUSIVE approach has been assessed with subjective and objective measurements and compared to that of interaction systems customarily used in industry. Results have shown that users appreciated the INCLUSIVE system and largely preferred it over the customary system. Moreover, with regard to objective performance-related measurements, they performed better when using the INCLUSIVE system since they received tailored guidance during the considered working tasks.
2021
- Hierarchical and Flexible Traffic Management of Multi-AGV Systems Applied to Industrial Environments
[Relazione in Atti di Convegno]
Pratissoli, Federico; Battilani, Nicola; Fantuzzi, Cesare; Sabattini, Lorenzo
abstract
2021
- Knowledge-Based Automation for Smart Manufacturing Systems
[Articolo su rivista]
Vogel-Heuser, B.; Ju, F.; Fantuzzi, C.; Lu, Y.; Hess, D.
abstract
2021
- Optimized power modulation in wave based bilateral teleoperation
[Articolo su rivista]
Ferraguti, Federica; Bonfe, Marcello; Fantuzzi, Cesare; Secchi, Cristian
abstract
2021
- Smart Node Networks Orchestration: A New E2E Approach for Analysis and Design for Agile 4.0 Implementation
[Articolo su rivista]
Bertoli, Annalisa; Cervo, Andrea; Rosati, Carlo Alberto; Fantuzzi, Cesare
abstract
2021
- The INCLUSIVE System: A General Framework for Adaptive Industrial Automation
[Articolo su rivista]
Villani, Valeria; Sabattini, Lorenzo; Baranska, Paulina; Callegati, Enrico; Czerniak, Julia N.; Debbache, Adel; Fahimipirehgalin, Mina; Gallasch, Andreas; Loch, Frieder; Maida, Rosario; Mertens, Alexander; Mockallo, Zofia; Monica, Francesco; Nitsch, Verena; Talas, Engin; Toschi, Elisabetta; Vogel-Heuser, Birgit; Willems, Jeanmarc; Zolnierczyk-Zreda, Dorotadorota; Fantuzzi, Cesare
abstract
2021
- Toward Future Automatic Warehouses: An Autonomous Depalletizing System Based on Mobile Manipulation and 3D Perception
[Articolo su rivista]
Aleotti, Jacopo; Baldassarri, Alberto; Bonfè, Marcello; Carricato, Marco; Chiaravalli, Davide; Di Leva, Roberto; Fantuzzi, Cesare; Farsoni, Saverio; Innero, Gino; Lodi Rizzini, Dario; Melchiorri, Claudio; Monica, Riccardo; Palli, Gianluca; Rizzi, Jacopo; Sabattini, Lorenzo; Sampietro, Gianluca; Zaccaria, Federico
abstract
This paper presents a mobile manipulation platform designed for autonomous depalletizing tasks. The proposed solution integrates machine vision, control and mechanical components to increase flexibility and ease of deployment in industrial environments such as warehouses. A collaborative robot mounted on a mobile base is proposed, equipped with a simple manipulation tool and a 3D in-hand vision system that detects parcel boxes on a pallet, and that pulls them one by one on the mobile base for transportation. The robot setup allows to avoid the cumbersome implementation of pick-and-place operations, since it does not require lifting the boxes. The 3D vision system is used to provide an initial estimation of the pose of the boxes on the top layer of the pallet, and to accurately detect the separation between the boxes for manipulation. Force measurement provided by the robot together with admittance control are exploited to verify the correct execution of the manipulation task. The proposed system was implemented and tested in a simplified laboratory scenario and the results of experimental trials are reported.
2021
- Worker satisfaction with adaptive automation and working conditions: a theoretical model and questionnaire as an assessment tool
[Articolo su rivista]
Villani, Valeria; Sabattini, Lorenzo; Żołnierczyk-Zreda, Dorota; Mockałło, Zofia; Barańska, Paulina; Fantuzzi, Cesare
abstract
2020
- A Control Barrier Function Approach for Maximizing Performance while Fulfilling to ISO/TS 15066 Regulations
[Articolo su rivista]
Ferraguti, F.; Bertuletti, M.; Landi, C. T.; Bonfe, M.; Fantuzzi, C.; Secchi, C.
abstract
ISO/TS 15066 is globally recognized as the guideline for designing safe collaborative robotic cells, where human and robot collaborate in order to fulfill a common job. Current approaches for implementing the ISO/TS 15066 guidelines lead to a conservative behavior (e.g. low velocity) of the robot and, consequently, to poor performance of the collaborative cell. In this letter, we propose an approach based on control barrier functions that allows to maximize the performance of a robot acting in a collaborative cell while satisfying the ISO/TS 15066 regulations. The proposed approach has been successfully validated both in simulation and through experiments.
2020
- Air Quality Monitoring in a BIM model by means of a IoT Sensors Network
[Relazione in Atti di Convegno]
Rosati, C. A.; Cervo, A.; Fantuzzi, C.
abstract
BIM (Building Information Modeling) is an object-oriented approach for the digital modeling of buildings and infrastructures, a centralized system for sharing technical information among all Stakeholders during the entire life cycle of the structure. BIM is at the same time a tool for planning, evaluation, monitoring and documentation; however, some constraints determine a potential gap between represented reality and actual reality. This gap is determined by the fact that the information within the system is updated manually by expert designers, losing substantial synchronization with the real system under analysis. The risk is also to have a so extensive dataset to make its update management complex for a human user. Currently, to achieve direct interaction between civil structures and digital modeling systems, the scientific community is carrying out researches for the application of digital twin concepts in the field of construction automation. In particular, studies about the integration between IoT sensor networks and BIM start to be explored. The project described in this paper aims to propose such integration with a specific focus on air quality parameters monitoring, leveraging on scalable approaches. The data updating system is based on a distributed IoT sensor network, designed and implemented using free and open-source software; the communication protocols are all based on open broker-based technologies, like MQTT, and the data dashboard aimed to visualize real-time data and historical data series are based on web applications over HTTP. The research project led to the creation of a sensorized and BIM-modeled hub which demonstrates the validity of the concept.
2020
- Guest Editorial Special Section on the 2018 Conference on Automation Science and Engineering (CASE)
[Abstract in Rivista]
Fantuzzi, C.; Fay, A.; Frey, G.; Vogel-Heuser, B.
abstract
2020
- Humans interacting with multi-robot systems: a natural affect-based approach
[Articolo su rivista]
Villani, V.; Capelli, B.; Secchi, C.; Fantuzzi, C.; Sabattini, L.
abstract
This paper proposes a novel human–multi-robot-system interaction approach that enjoys two main features: natural interaction and affect-based adaptation of robots behavior. Specifically, the proposed system enables interaction by means of a wrist-worn device, such as a commercial smartwatch, which allows to track user’s movements and heart activity. Thus, on the one side, the proposed system allows the user to intuitively drive the robots by establishing a natural mapping between wrist movements and robots velocity. On the other side, the system estimates user’s mental fatigue during interaction by means of the analysis of heart rate variability. The proposed interaction system adapts then the behavior of the multi-robot system when the interacting user gets overwhelmed with the interaction and control task, which is then simplified. Experimental validation is provided, to show the effectiveness of the proposed system. First, the natural and affect-based interaction are considered separately. Then, the approach is tested considering a complex realistic scenario, which is simulated in virtual reality in order to get an immersive and realistic interaction experience. The results of the experimental validation clearly show that the proposed affect-based adaptive system leads to relieving the user’s fatigue and mental workload.
2020
- Safety barrier functions and multi-camera tracking for human–robot shared environment
[Articolo su rivista]
Ferraguti, Federica; Talignani Landi, Chiara; Costi, Silvia; Bonfè, Marcello; Farsoni, Saverio; Secchi, Cristian; Fantuzzi, Cesare
abstract
A new vision in human–robot collaboration has allowed to place robots nearby human operators, working close to each other in industrial environments. As a consequence, human safety has become a dominant issue, together with production efficiency. In this paper we propose an optimization-based control algorithm that allows robots to avoid obstacles (like human operators) while minimizing the difference between the nominal acceleration input and the commanded one. Control Barrier Functions are exploited to build safety barriers around each robot link, to guarantee collision-free trajectories along the whole robot body. Human accelerations and velocities are computed by means of a bank of Kalman filters. To solve obstruction problems, two RGB-D cameras are used and the measured skeleton data are processed and merged using the mentioned bank of Kalman filters. The algorithm is implemented on an Universal Robots UR5 in order to validate the proposed approach.
2020
- Teleoperation of Multi-Robot Systems to Relax Topological Constraints
[Relazione in Atti di Convegno]
Sabattini, L.; Capelli, B.; Fantuzzi, C.; Secchi, C.
abstract
Multi-robot systems are able to achieve common objectives exchanging information among each other. This is possible exploiting a communication structure, usually modeled as a graph, whose topological properties (such as connectivity) are very relevant in the overall performance of the multirobot system. When considering mobile robots, such properties can change over time: robots are then controlled to preserve them, thus guaranteeing the possibility, for the overall system, to achieve its goals. This, however, implies limitations on the possible motion patterns of the robots, thus reducing the flexibility of the overall multi-robot system. In this paper we introduce teleoperation as a means to reduce these limitations, allowing temporary violations of topological properties, with the aim of increasing the flexibility of the multi-robot system.
2019
- A General Approach to Natural Human-Robot Interaction
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Villani, Valeria; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper proposes a scheme for letting a human interact with a generic robot in a natural manner. Based on the concept of natural user interfaces, the proposed methods exploit recognition of the users’ forearm motion to produce commands for the robotic system. High-level commands are provided based on gesture recognition, and velocity commands are computed for the robot by mapping, in a natural manner, the motion of the user’s forearm. The method is proposed in a general manner, and is then instantiated considering two different robotic systems, namely a quadrotor and a wheeled mobile robot. Usability of the system is evaluated with experiments involving users.
2019
- A General Methodology for Adapting Industrial HMIs to Human Operators
[Articolo su rivista]
Villani, Valeria; Sabattini, Lorenzo; Loch, Frieder; Vogel-Heuser, Birgit; Fantuzzi, Cesare
abstract
Modern production systems are becoming more and more complex to comply with diversified market needs, flexible production, and competitiveness. Despite technological progress, the presence of human operators is still fundamental in production plants, since they have the important role of supervising and monitoring processes, by interacting with such complex machines. The complexity of machines implies an increased complexity of human-machine interfaces (HMIs), which are the main point of contact between the operator and the machine. Thus, HMIs cannot be considered anymore an accessory to the machine and their improvement has become an important part of the design of the whole machines, to enable a nonstressful interaction and make them easy to also use less skilled operators. In this article, we present a general framework for the design of HMIs that adapt to the skills and capabilities of the operator, with the ultimate aim of enabling a smooth and efficient interaction and improving user's situation awareness. Adaptation is achieved by considering three different levels: Perception (i.e., how information is presented), cognition (i.e., what information is presented), and interaction (i.e., how interaction is enabled). For each level, general guidelines for adaptation are provided, thus defining a meta-HMI independent of the application. Finally, some examples of how the proposed adaptation patterns can be applied to the case of procedural and extraordinary maintenance tasks are presented. Note to Practitioners-This article was motivated by the problem of facilitating the interaction of human operators with human-machine interfaces (HMIs) of complex industrial systems. Standard industrial HMIs are static and do not consider the user's characteristics. As a consequence, least-skilled operators are prevented from their use and/or have poor performance. In this article, we suggest a novel methodology to the design of adaptive industrial HMIs that adapt to the skills and capabilities of operators and compensate their limitations (e.g., due to age or inexperience). In particular, we propose a methodological framework that consists of general rules to accommodate the user's characteristics. Adaptation is achieved at three different levels: Perception (i.e., how information is presented), cognition (i.e., what information is presented), and interaction (i.e., how interaction is enabled). The presented rules are independent of the target application. Nevertheless, we establish a relationship between such design rules and user's impairments and capabilities and kind of working tasks. Hence, designers of HMIs are called to instantiate them considering the specific requirements and characteristics of the users and the working tasks of the application at hand.
2019
- A Methodology for Comparative Analysis of Collaborative Robots for Industry 4.0
[Relazione in Atti di Convegno]
Ferraguti, F.; Pertosa, A.; Secchi, C.; Fantuzzi, C.; Bonfe, M.
abstract
Collaborative robots are one of the key drivers in Industry 4.0 and they have evolved considerably since the last decades of the 20th century. With respect to the industrial robots, collaborative robots are more productive, flexible, versatile and safer. In the recent years, many industrial robot producers and startups entered the segment of collaborative robots. In this paper, we propose a methodology for developing a comparative analysis of the collaborative robots currently available in the market. The goal of the paper is to provide a framework for allowing the benchmarking, based on common robot parameters and standardized experiments that can be performed with the robot under investigation. An experimental technological review of three different collaborative robots is provided, to show how the methodology can be applied in real cases.
2019
- A passivity-based strategy for manual corrections in human-robot coaching
[Articolo su rivista]
Landi, Chiara Talignani; Ferraguti, Federica; Fantuzzi, Cesare; Secchi, Cristian
abstract
In recent years, new programming techniques have been developed in the human-robot collaboration (HRC) field. For example, walk-through programming allows to program the robot in an easy and intuitive way. In this context, a modification of a portion of the trajectory usually requires the teaching of the path from the beginning. In this paper we propose a passivity-based method to locally change a trajectory based on a manual human correction. At the beginning the robot follows the nominal trajectory, encoded through the Dynamical Movement Primitives, by setting high control gains. When the human grasps the end-effector, the robot is made compliant and he/she can drive it along the correction. The correction is optimally joined to the nominal trajectory, resuming the path tracking. In order to avoid unstable behaviors, the variation of the control gains is performed exploiting energy tanks, preserving the passivity of the interaction. Finally, the correction is spatially fixed so that a variation in the boundary conditions (e.g., the initial/final points) does not affect the modification.
2019
- A variable admittance control strategy for stable physical human–robot interaction
[Articolo su rivista]
Ferraguti, Federica; Talignani Landi, Chiara; Sabattini, Lorenzo; Bonfè, Marcello; Fantuzzi, Cesare; Secchi, Cristian
abstract
Admittance control allows a desired dynamic behavior to be reproduced on a non-backdrivable manipulator and it has been widely used for interaction control and, in particular, for human–robot collaboration. Nevertheless, stability problems arise when the environment (e.g. the human) the robot is interacting with becomes too stiff. In this paper, we investigate the stability issues related to a change of stiffness of the human arm during the interaction with an admittance-controlled robot. We propose a novel method for detecting the rise of instability and a passivity-preserving strategy for restoring a stable behavior. The results of the paper are validated on two robotic setups and with 50 users performing two tasks that emulate industrial operations.
2019
- An Adaptive Virtual Training System Based on Universal Design
[Relazione in Atti di Convegno]
Loch, Frieder; Fahimipirehgalin, Mina; Czerniak, Julia N.; Mertens, Alexander; Villani, Valeria; Sabattini, Lorenzo; Fantuzzi, Cesare; Vogel-Heuser, Birgit
abstract
The increasing complexity of manufacturing environments requires effective training systems to prepare the operation personnel for their tasks. Several training systems have been proposed. A common approach is the application of virtual environments to train interactions with an industrial machine in a safe, attractive, and efficient way. However, these training systems cannot adapt to the requirements of an increasingly diversified workforce. This paper introduces an approach for the design of an adaptive virtual training system based on the idea of universal design. The system is based on a two-step approach that consists of an initial adaptation to the user capabilities and real-time adaptations during training based on measurements of the user. The adaptations concern the use of different representations of lessons with different complexity and interaction modalities. The proposed approach provides a flexible training system that can adapt to the needs of a broad group of users.
2019
- Augmented reality based approach for on-line quality assessment of polished surfaces
[Articolo su rivista]
Ferraguti, Federica; Pini, Fabio; Gale, Thomas; Messmer, Franck; Storchi, Chiara; Leali, Francesco; Fantuzzi, Cesare
abstract
Augmented reality is considered one of the enabling technologies of the fourth industrial revolution, within the Industry 4.0 program and beyond. Indeed, augmented reality solutions can increase the working quality and the productivity and allow a better use of the human resources. This technology can help the operator in the industrial applications during the crucial phases of the processes. Since the quality assessment of the surfaces is recognized to be a key phase in the polishing process, in this paper we propose a novel method that exploits augmented reality to support the operators during this phase. The metrology data measured by a surface measurement system are directly projected on the polished component through an augmented reality headset worn by the operators and used to assess the quality of the worked surfaces. Rather than imagine how a certain parameter change can affect the result achieved, the information is directly there on the component's surface. Users can see from the data where refinements are required and make better and faster decisions, which is compelling for its potential beyond industrial polishing. The proposed method is implemented and validated on an industrial cell, where the robot automatically perform the polishing task and move the head of the surface measurement system along the surface to measure the metrology parameters. Thanks to the proposed approach, the end-user and the operator can directly see on the component if the quality reached satisfies the specifications or if some parts of the surface require further refinements through additional polishing steps.
2019
- Challenges of interdisciplinary development of Cyber-Physical Production Systems
[Articolo su rivista]
Vogel-Heuser, B.; Fantuzzi, C.; Wimmer, M.; Bohm, M.; Fay, A.
abstract
Model-based systems engineering has gained increasing application in the industrial development of a large number of technical systems. The use of various models is decisive for interdisciplinary innovations. However, it also comprises many challenges. The first challenge is the heterogeneous model landscape, which is characterized in particular by overlapping, partially redundantly modelled information. Second, the development, production and service processes are constantly subject to internal and external development cycles. To overcome these challenges, various methods and techniques can be used. In this paper, different approaches are investigated regarding their advantages and limitations: inconsistency management of coupled models in engineering, cross-disciplinary management of the engineering workflow, and the importance of smart data approaches.
2019
- Decentralized line equipment detection and production control by multi-agent technology
[Relazione in Atti di Convegno]
Cervo, A.; Goldoni, G.; Fantuzzi, C.; Borsari, R.
abstract
The complexity of modern industrial production systems and the persistent connectivity at the local level of manufacturing resources by means of IoT technologies are encouraging the study of increasingly flexible and reconfigurable control methods. Currently industrial software agents are mainly used for controlling job-shop organized systems, relying on negotiation mechanisms between Product agents and Resource agents. In this paper instead, we aim to develop a distributed production line controller, using agent-based technology for designing decentralized and communicating local state machines. The objective of the study is to obtain a global control system deriving from the interaction and exchange of information between software agents associated with each machine on the production line. The controller implemented has the purpose of eliminating the central infrastructure, generally present in industrial automation systems: the goal is to move the decision-making process locally by associating intelligent entities to each machine. The advantage of decentralization lies in the possibility of having a modular, flexible and reconfigurable line controller concept: indeed, there is no supervisor aware of the entire system to control. The agents can also collaborate for a line detection in case of very complex line without there being statistical evidence of performance deterioration. To validate the functionality of this approach, experimental tests were conducted in a virtual environment.
2019
- Measurement and classification of human characteristics and capabilities during interaction tasks
[Articolo su rivista]
Villani, V.; Czerniak, J. N.; Sabattini, L.; Mertens, A.; Fantuzzi, C.
abstract
In this paperwe address the need to design adaptive interacting systems for advanced industrial production machines. Modern production systems have become highly complex and include many subsidiary functionalities, thus making it difficult for least skilled human operators interact with them. In this regard, adapting the behavior of the machine and of the operator interface to the characteristics of the user allows a more effective interaction process, with a positive impact on manufacturing efficiency and user's satisfaction. To this end, it is crucial to understandwhich are the user's capabilities that influence the interaction and, hence, should be measured to provide the correct amount of adaptation.Moving along these lines, in this paper we identify groups of users that, despite having different individual capabilities and features, have common needs and response to the interaction with complex production systems. As a consequence,we define clusters of users that have the same need for adaptation. Then, adaptation rules can be defined by considering such users' clusters, rather than addressing specific individual user's needs.
2019
- New trends in the design of human-machine interaction for CNC machines
[Relazione in Atti di Convegno]
Lotti, Giulia; Villani, Valeria; Battilani, Nicola; Fantuzzi, Cesare
abstract
2019
- Survey on usability assessment for industrial user interfaces
[Relazione in Atti di Convegno]
Villani, Valeria; Lotti, Giulia; Battilani, Nicola; Fantuzzi, Cesare
abstract
2019
- Systematic Approach to Develop a Flexible Adaptive Human-Machine Interface in Socio-Technological Systems
[Relazione in Atti di Convegno]
Czerniak, J. N.; Villani, V.; Sabattini, L.; Loch, F.; Vogel-Heuser, B.; Fantuzzi, C.; Brandl, C.; Mertens, A.
abstract
Modern automatic machines in production have been becoming more and more complex within the recent years. Thus, human-machine interfaces (HMI) reflect multiple different functions. An approach to improve human-machine interaction can be realised by adjusting the HMI to the operators’ requirements and complementing their individual skills and capabilities, supporting them in self-reliant machine operation. Based on ergonomic concepts of information processing, we present a systematic approach for developing an adaptive HMI after the MATE concept (Measure, Adapt & Teach). In a first step, we develop a taxonomy of human capabilities that have an impact on individual performance during informational work tasks with machine HMI. We further evaluate three representative use cases by pairwise comparison regarding the classified attributes. Results show that cognitive information processes, such as different forms of attention and factual knowledge (crystalline intelligence) are most relevant on average. Moreover, perceptive capabilities that are restricted by task environment, e.g. several auditory attributes; as well as problem solving demand further support, according to the experts’ estimation.
2019
- Teleoperation of a Multi-robot System with Adjustable Dynamic Parameters
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Fantuzzi, Cesare; Secchi, Cristian
abstract
Teleoperation of a Multi-Robot System with Adjustable Dynamic Parameters
2019
- TIREBOT: A collaborative robot for the tire workshop
[Articolo su rivista]
Levratti, Alessio; Riggio, Giuseppe; Fantuzzi, Cesare; De Vuono, Antonio; Secchi, Cristian
abstract
Collaborative robots allow to relieve humans from tedious and/or tiring tasks while leaving to the operator high-level activities, where their expertise is needed. In this paper the mechanical design and the collaborative control of TIREBOT, a robotic assistant helping tire workshop operators in the wheel replacement process, is illustrated. The effectiveness of TIREBOT is validated in a real tire-workshop. Furthermore, the possibility of using TIREBOT as an autonomous personal forklift has been validated in an industrial scenario.
2018
- A Framework for Affect-Based Natural Human-Robot Interaction
[Relazione in Atti di Convegno]
Villani, Valeria; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we present a general framework for affective human-robot interaction that allows users to intuitively interact with a robot and takes into account their mental fatigue, thus simplifying the task or providing assistance when the user feels stressed. Interaction with the robot is achieved by naturally mapping user's forearm motion, detected with a smartwatch, into robot's motion. High-level commands can be provided by means of gestures. An approach based on affective robotics is used to adapt the level of robot's autonomy to the cognitive workload of the user. User's mental fatigue is detected from the analysis of heart rate, also measured by the smartwatch. The framework is general and can be applied to different robotic systems. In this paper, we consider its experimental validation on a wheeled mobile robot.
2018
- A Low-Cost Navigation Strategy for Yield Estimation in Vineyards
[Relazione in Atti di Convegno]
Riggio, Giuseppe; Fantuzzi, Cesare; Secchi, Cristian
abstract
Accurate yield estimation is very important for improving the vineyard management, the quality of the grapes and the health of the vines. The most common systems use RGB image processing for achieving a good estimation. In order to collect images, robots or farming vehicles can be equipped with a RGB camera. In this paper, we propose a low-cost autonomous system which can navigate through a vineyard while collecting grape pictures in order to provide a yield estimation. Our system uses only a laser scanner to detect the row and follows it until its end, then it navigates towards the next one, exploiting the knowledge of the vineyard. The navigation algorithm was tested both in simulation and in a real environment with good results. Furthermore, a yield estimation of two different grape varieties is presented.
2018
- A Passivity-Based Strategy for Coaching in Human-Robot Interaction
[Relazione in Atti di Convegno]
Landi, Chiara Talignani; Ferraguti, Federica; Fantuzzi, Cesare; Secchi, Cristian
abstract
In order to make robot programming more easy and immediate, walk-through programming techniques can be exploited. However, a modification of a portion of the trajectory usually means to execute the path from the beginning. In this paper we propose a passivity-based framework to modify the trajectory online, manually driving the robot throughout the desired correction. The system follows the initial trajectory, encoded with Dynamical Movement Primitives, by setting high gains in the admittance control. When the human operator grabs the end-effector, the robot becomes compliant and the user can easily teach the desired correction, until he/she releases it at the end of the modification. Finally, the correction is optimally joined to the initial trajectory, restarting the path tracking. To avoid unsafe behaviors, the variation of the admittance parameters is performed exploiting energy tanks, in order to preserve the passivity of the interaction.
2018
- An Adaptive Speech Interface for Assistance in Maintenance and Changeover Procedure
[Relazione in Atti di Convegno]
Loch, Frieder; Czerniak, Julia; Villani, Valeria; Sabattini, Lorenzo; Fantuzzi, Cesare; Mertens, Alexander; Vogel-Heuser, Birgit
abstract
Machine operators remain important in future production environments and need intuitive and powerful interaction techniques. Many assistance and support applications for machine operators use speech-based interfaces since they are suitable during manual tasks and when visual attention cannot be occupied. Due to developments like the demographic change or the need for skilled personnel, the skills and capabilities of the workers will become increasingly diverse. Speech-based interfaces therefore need to be adaptable to the capabilities, limitations and preferences of individual operators. This paper addresses this requirement and proposes an adaptive speech interface that supports machine operators during maintenance and changeover procedures. All aspects of the proposed application can be adapted to the requirements of the user. The system uses a process model, instruction templates, a user model, and a model of the input vocabulary to describe the components of the application. This allows a flexible adaptation of the speech interface and the provided instructions to the requirements of individual users and to further use cases.
2018
- An Industrial Social Network for Sharing Knowledge Among Operators
[Relazione in Atti di Convegno]
Villani, Valeria; Sabattini, Lorenzo; Levratti, Alessio; Fantuzzi, Cesare
abstract
Due to the increasing complexity of modern automatic machines typically used in several industrial applications, the need for assistive technologies is becoming very relevant. Typical approaches consist in designing advanced and adaptive human-machine interfaces (HMIs) that can be effectively used by any operator and that provide guided procedures for the most common situations. However, when dealing with complex systems, infrequent and unforeseen situations may happen, whose solution require the experience owned by a limited number of skilled operators. To this end, in this paper we propose an industrial social network concept to allow an effective exchange of information among the operators and to facilitate the solution of unforeseen events, such as unscheduled maintenance activities or troubleshooting.
2018
- Big Data for advanced monitoring system: An approach to manage system complexity
[Relazione in Atti di Convegno]
Longo, C. S.; Fantuzzi, C.; Monica, F.; Manfredotti, L.; Sorge, M.
abstract
Big Data is the nowadays world current trend. Millions of sensors are connected to the everyday life devices, ingesting petabytes of data per day and helping companies improve their products. This paper provides an example of connecting the automation world with the Big Data world: sensor data streamed by real world operating machines is stored in databases, analysed and displayed in real-time dashboards with the intent of tracking the machines operating status and alerting the technicians in case maintenance is needed.
2018
- Controlling the interaction of a multi-robot system with external entities
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we consider a multi-robot system
that shares the environment with external entities, and we
propose a methodology for controlling the interaction with
them. In particular, we consider the problem of achieving
a desired dynamic interaction model, in such a way that
the multi-robot system exchanges desired forces with external
entities. This is obtained by introducing local deformations of
the coupling actions among the robots. The proposed method
ensures preservation of the passivity property, which provides
safety guarantees in the interaction with the (possibly poorly
known) external entities.
2018
- MATE Robots Simplifying My Work: The Benefits and Socioethical Implications
[Articolo su rivista]
Villani, Valeria; Sabattini, Lorenzo; Czerniak, Julia N.; Mertens, Alexander; Fantuzzi, Cesare
abstract
With the increasing complexity of modern industrial automatic and robotic systems, an increasing burden is put on the operators, who are requested to supervise and interact with very complex systems, typically under challenging and stressful conditions. To overcome this issue, it is necessary to adopt a responsible approach based on the anthropocentric design methodology, such that machines adapt to the humans capabilities, and not vice versa. Moving along these lines, in this paper we consider an integrated methodological design approach, which we call MATE, consisting in devising complex automatic or robotic solutions that measure current operator's status, adapting the interaction accordingly, and providing her/him with proper training to improve the interaction and learn lacking skills and expertise. Accordingly, a MATE system is intended to be easily usable for all users, thus meeting the principles of inclusive design. Using such a MATE system gives rise to several ethical and social implications, which are discussed in this paper. Additionally, a discussion about which factors in the organization of companies are critical with respect to the introduction of a MATE system is presented.
2018
- Methodological Approach for the Evaluation of an Adaptive and Assistive Human-Machine System
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Villani, Valeria; Fantuzzi, Cesare; Czerniak, Julia N.; Mertens, Alexander; Loch, Frieder; Vogel-Heuser, Birgit
abstract
With the increasing complexity of modern industrial automatic and robotic systems, an increasing burden is put on the operators, who are requested to supervise and interact with such complex systems, typically under challenging and stressful conditions. To overcome this issue, it is necessary to adopt a responsible approach based on the anthropocentric design methodology, such that machines adapt to the humans capabilities. Moving along these lines, a methodological approach called MATE was introduced in [1], which consists in devising complex automatic or robotic solutions that measure current operator's status, adapting the interaction accordingly, and providing her/him with proper training to improve the interaction and learn lacking skills and expertise. In this paper we propose an evaluation and validation procedure to guarantee the achievement of the requirements of a MATE system.
2018
- On the Use of Energy Tanks for Multi-Robot Interconnection
[Relazione in Atti di Convegno]
Riggio, Giuseppe; Fantuzzi, Cesare; Secchi, Cristian
abstract
In multi-robot systems passive interconnections among agents are often exploited to achieve a desired and robustly stable cooperative behavior. Nevertheless, the passivity constraint limits the kinds of behaviors that can be achieved. In this paper, we exploit the concept of energy tank for building a novel generalized interconnection that allows to impose any kind of dynamic coupling between two passive systems in a flexible way while preserving the passivity of the overall coupled system. The proposed strategy is validated by simulations and experiments.
2018
- Passivity preserving force scaling for enhanced teleoperation of multirobot systems
[Articolo su rivista]
Sabattini, Lorenzo; Secchi, Cristian; Capelli, Beatrice; Fantuzzi, Cesare
abstract
In this letter, we address the problem of teleoperating a multirobot system, and we propose a methodology for letting the user teleoperate the group of robots according to some desired dynamic behavior. Specifically, we propose a novel methodology for the teleoperation of multirobot systems, where a local control action and interrobot relationships are tuned in order to reduce their effect on the force feedback perceived by the operator. The proposed methodology is developed guaranteeing preservation of the passivity property. The effectiveness of the proposed teleoperation scheme is validated experimentally, on real robots and in a virtual reality environment.
2018
- Relieving operators’ workload: Towards affective robotics in industrial scenarios
[Articolo su rivista]
TALIGNANI LANDI, Chiara; Villani, Valeria; Ferraguti, Federica; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper proposes a novel approach based on affective robotics that can be applied to industrial applications. Considering a human-robot interaction task, we propose to analyze the mental workload of the operator, and subsequently adapt the behavior of the robotic system, introducing assistive technologies. These technologies would prevent the performances deterioration caused by the human stress, helping him/her only when needed and decreasing the user's mental workload. This represents a general methodology, which can be applied to several industrial applications, leading to increase the overall performances of human-robot interaction exploiting principles of human-centered design. As a case study, we consider a teleoperation task, where virtual fixtures are utilized as an assistive technology. The stress of the operator is monitored in terms of heart rate variability, measured by means of a wearable sensor tied at the operator's wrist. Experimental validation of the proposed architecture is performed on a group of 15 users that teleoperate an industrial robot for performing a pick and place task.
2018
- Shaping the force feedback by dynamic scaling in the teleoperation of multi-robot systems
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Fantuzzi, Cesare; Secchi, Cristian
abstract
In passivity based bilateral teleoperation of multi-robot systems the coupling among
the robots produces unwanted dynamic effects that deteriorates the force fed back to the user.
In this paper we propose a passivity based dynamic scaling strategy for compensating these
disturbing terms. The effectiveness of the proposed methodology is experimentally validated.
2018
- Simulation and optimization of industrial production lines
[Articolo su rivista]
Longo, Claudio Santo; Fantuzzi, Cesare
abstract
Simulation and optimization techniques are the pillars of for the Virtual Commissioning of modern digital factories. In particular, industrial production lines are complex systems formed by a set of machines that have several cross-dependencies (i. e., the production efficiency of a machine impact deeply performance figures of the others and affects the whole line productivity). The simulation and optimization of production lines is an integrated approach that allows finding efficiently optimized production parameters. This paper presents an example of application of the simulation to the virtual design and optimization of an industrial production line.
2018
- Survey on Human-Robot Interaction for Robot Programming in Industrial Applications
[Capitolo/Saggio]
Villani, Valeria; Pini, Fabio; Leali, Francesco; Secchi, Cristian; Fantuzzi, Cesare
abstract
The recent trends in modern industry highlight an increasing use of robots for a wide range of applications, which span from established manufacturing operations to novel tasks characterized by a close collaboration with the operators. Although human-robot collaboration allows to relieve operators of exhausting works, an effective collaboration requires a straightforward interaction to foster the use of robot assistants. This paper provides a comprehensive survey on human-robot interaction approaches and related interfaces addressed to robot programming. An overview of on-line and off-line robot programming techniques is first presented. Then, novel intuitive interaction means, such as those based on multi-modal interaction, virtual and augmented reality, are considered. The paper aims at pointing out that collaborative robotics can effectively reduce operator's physical workload if easy to use interfaces for robot programming are provided.
2018
- The PAN-Robots Project: Advanced Automated Guided Vehicle Systems for Industrial Logistics
[Articolo su rivista]
Sabattini, Lorenzo; Aikio, Mika; Beinschob, Patric; Boehning, Markus; Cardarelli, Elena; Digani, Valerio; Krengel, Annette; Magnani, Massimiliano; Mandici, Szilard; Oleari, Fabio; Reinke, Christoph; Ronzoni, Davide; Stimming, Christian; Varga, Robert; Vatavu, Andrei; Castells Lopez, Sergi; Fantuzzi, Cesare; Mayra, Aki; Nedevschi, Sergiu; Secchi, Cristian; Fuerstenberg, Kay
abstract
In modern manufacturing plants, automation is widely adopted in the production phases, which leads to achieving a high
level of productivity and efficiency. However, the same level of automation is generally not achieved in logistics, that is
typically performed by human operators, and manually driven vehicles. In fact, even though Automated Guided Vehicles
(AGVs) have been used for a few decades for goods transportation in industrial environments [1], they do not represent
a widespread solution yet, and are typically applied only in specific scenarios.
2018
- Towards an integrated approach for supporting the workers in Industry 4.0
[Relazione in Atti di Convegno]
Lotti, Giulia; Villani, Valeria; Battilani, Nicola; Fantuzzi, Cesare
abstract
Assisting and supporting human operators in modern industry is becoming crucial to increase the efficiency. Available tools, like use and maintenance manual, have a complex organization due to variety of information treated and purposes. Confusion and disorientation bring a series of disadvantages that increase the cognitive effort of the users. Tasks such as set-up, maintenance, and troubleshooting, strongly depend on the skills of human operators.
To tackle this problem, in this paper we present an integrated approach with the aim of developing a thorough system that starts from a structured management of technical documen- tation and provides useful support to the users during their work. The approach is composed by three phases i) Data organization and management, obtaining with a standard that allows to edit and manage the information in a structured way; ii) Content extraction and filtering, for collecting the technical labelled information; iii) Support to the user during use and maintenance of the machine, consisting in a set of on-line tools. At the end of this paper, we present an application of the proposed approach to the specific case of troubleshooting support, by considering MyAID, a tool designed to assist operators to solve machine failures.
2017
- A Natural Infrastructure-Less Human–Robot Interaction System
[Articolo su rivista]
Villani, Valeria; Sabattini, Lorenzo; Riggio, Giuseppe; Secchi, Cristian; Minelli, Marco; Fantuzzi, Cesare
abstract
This letter introduces a novel methodology for letting a user interact with a robotic system in a natural manner. The main idea is that of defining an interaction system that does not require any specific infrastructure or device but relies on commonly utilized objects while leaving the user’s hands free. Specifically, we propose to utilize a smartwatch (or any commercial sensorized wristband) for recognizing the motion of the user’s forearm. This is achieved by measuring accelerations and angular velocities, which are then elaborated for recognizing gestures and for defining velocity commands for the robot. The proposed interaction system is evaluated experimentally with different users controlling a semiautonomous quadrotor. Results show that the usability and effective- ness of the proposed natural interaction system provide significant improvement in the human–robot interaction experience.
2017
- Achieving the desired dynamic behavior in multi-robot systems interacting with the environment
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we consider the problem of controlling the dynamic behavior of a multi-robot system while interacting with the environment. In particular, we propose a general methodology that, by means of locally scaling interrobot coupling relationships, leads to achieving a desired interactive behavior. The proposed method is shown to guarantee passivity preservation, which ensures a safe interaction. The performance of the proposed methodology is evaluated in simulation, over large-scale multi-robot systems.
2017
- Admittance control parameter adaptation for physical human-robot interaction
[Relazione in Atti di Convegno]
Landi, Chiara Talignani; Ferraguti, Federica; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In physical human-robot interaction, the coexistence of robots and humans in the same workspace requires the guarantee of a stable interaction, trying to minimize the effort for the operator. To this aim, the admittance control is widely used and the appropriate selection of the its parameters is crucial, since they affect both the stability and the ability of the robot to interact with the user. In this paper, we present a strategy for detecting deviations from the nominal behavior of an admittance-controlled robot and for adapting the parameters of the controller while guaranteeing the passivity. The proposed methodology is validated on a KUKA LWR 4+.
2017
- Collision avoidance for multiple Lagrangian dynamical systems with gyroscopic forces
[Articolo su rivista]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
This article introduces a novel methodology for dealing with collision avoidance for groups of mobile robots. In particular, full dynamics are considered, since each robot is modeled as a Lagrangian dynamical system moving in a three-dimensional environment. Gyroscopic forces are utilized for defining the collision avoidance control strategy: This kind of forces leads to avoiding collisions, without interfering with the convergence properties of the multi-robot system's desired control law. Collision avoidance introduces, in fact, a perturbation on the nominal behavior of the system: We define a method for choosing the direction of the gyroscopic force in an optimal manner, in such a way that perturbation is minimized. Collision avoidance and convergence properties are analytically demonstrated, and simulation results are provided for validation purpose.
2017
- COMPARISON OF DIFFERENT AGILE METHODOLOGIES AND FIT ASSESSMENT IN AN INDUSTRIAL CONTEXT
[Articolo su rivista]
Margini, Andrea; Cutrona, Gaetano; Fantuzzi, Cesare
abstract
The paper collects together and describes the main and most known Agile methodologies. Those methodologies are then compared in order to assess their fit in the context of highly innovative non-software companies. In particular, the focus is on a full system supplier for food processing and packaging equipment, packaging material and services. The fit between the Agile methodologies and the company is performed considering the innovation and development processes in place into the Research and Development department of the company itself. By doing so the paper aims at contributing to the theme of Agile application in non-software industries. Moreover, it will support in the choice of which method or framework suits better having clear the needs and
characteristics of that specific context. Finally, the paper provides also a suggestion about how to approach this kind of choices.
2017
- Configuring the deployment into software-based controllers through hierarchical simulations
[Relazione in Atti di Convegno]
Barbieri, G.; Borsari, R.; Fantuzzi, C.
abstract
The deployment of control algorithms into software-based controllers is fundamental for the correctness of the designed application. Deployment involves both the configuration of design choices and the management of unpredictable behaviors of controllers. Tools and methodologies must be identified for supporting the activity. This paper proposes to break-down the deployment process into layers of abstraction. Simulations and modeling patterns are introduced for configuring the design choices of each abstraction layer. However, the verification of the approach through the application to real case studies will be matter of future works.
2017
- Cooperative cloud robotics architecture for the coordination of multi-AGV systems in industrial warehouses
[Articolo su rivista]
Cardarelli, Elena; Digani, Valerio; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we introduce a novel cloud robotics architecture that provides different functionalities to support enhanced coordination of groups of Automated Guided Vehicles (AGVs) used for industrial logistics. In particular, we define a cooperative data fusion system that, gathering data from different sensing sources, provides a constantly updated global live view of the industrial environment, for coordinating the motion of the AGVs in an optimized manner. In fact, local sensing capabilities are complemented with global information, thus extending the field of view of each AGV. This knowledge extension allows to support a cooperative and flexible global route assignment and local path planning in order to avoid congestion zones, obstacles reported in the global live view map and deal with unexpected obstacles in the current path. The proposed methodology is validated in a real industrial environment, allowing an AGV to safely perform an obstacle avoidance procedure.
2017
- Coordinated dynamic behaviors for multirobot systems with collision avoidance
[Articolo su rivista]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper, we propose a novel methodology for achieving complex dynamic behaviors in multirobot systems. In particular, we consider a multirobot system partitioned into two subgroups: 1) dependent and 2) independent robots. Independent robots are utilized as a control input, and their motion is controlled in such a way that the dependent robots solve a tracking problem, that is following arbitrarily defined setpoint trajectories, in a coordinated manner. The control strategy proposed in this paper explicitly addresses the collision avoidance problem, utilizing a null space-based behavioral approach: this leads to combining, in a non conflicting manner, the tracking control law with a collision avoidance strategy. The combination of these control actions allows the robots to execute their task in a safe way. Avoidance of collisions is formally proven in this paper, and the proposed methodology is validated by means of simulations and experiments on real robots.
2017
- Discrete time model of a two-station one-buffer serial system with inventory level-dependent operation
[Articolo su rivista]
Gebennini, Elisa; Grassi, Andrea; Fantuzzi, Cesare; Rimini, Bianca
abstract
The paper deals with the discrete-time discrete-state modeling of two-station one-buffer serial systems in which the condition of the first station (operative/idle) is controlled according to the inventory level of the intermediate buffer. Briefly, the first station is forced to remain idle each time the buffer fills up until it empties to a predefined inventory level (referred to as restarting-inventory level). Previous works have proved that this control policy, called restart policy, is effective when outage costs (e.g., waste production) are generated each time the first station restarts production after an interruption.
While the works currently available in the literature assume that the buffer has to become completely empty before allowing the first station to resume production, the proposed paper develops a new analytical Markov model in which the restarting-inventory level can be greater than zero and arbitrarily set in the range [2, N-2] , where N is the buffer size. The proposed model is solved in closed form by means of a partitioning procedure and a solution technique described in detail. Then, the most important performance measures are obtained as a function of the restarting-inventory level, the buffer size and the reliability parameters of both stations.
Finally, some numerical results are discussed in order to validate the model and draw some concluding remarks about the values of the restarting-inventory level which maximize the effective efficiency of the system.
2017
- Interacting With a Mobile Robot with a Natural Infrastructure-Less Interface
[Relazione in Atti di Convegno]
Villani, Valeria; Sabattini, Lorenzo; Riggio, Giuseppe; Levratti, Alessio; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we introduce a novel approach that enables users to interact with a mobile robot in a natural manner. The proposed interaction system does not require any specific infrastructure or device, but relies on commonly utilized objects while leaving the user’s hands free. Specifically, we propose to utilize a smartwatch (or a sensorized wristband) for recognizing the motion of the user’s forearm. Measurements of accelerations and angular velocities are exploited to recognize user’s gestures and define velocity commands for the robot. The proposed interaction system is evaluated experimentally with different users controlling a mobile robot and compared to the use of a remote control device for the teleoperation of robots. Results show that the usability and effectiveness of the proposed natural interaction system based on the use of a smartwatch provide significant improvement in the human-robot interaction experience.
2017
- Methodological approach for the design of a complex inclusive human-machine system
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Villani, Valeria; Czerniak, Julia N.; Mertens, Alexander; Fantuzzi, Cesare
abstract
Modern industrial automatic machines and robotic cells are equipped with highly complex human-machine interfaces (HMIs) that often prevent human operators from an effective use of the automatic systems. In particular, this applies to vulnerable users, such as those with low experience or education level, the elderly and the disabled. To tackle this issue, it becomes necessary to design user-oriented HMIs, which adapt to the capabilities and skills of users, thus compensating their limitations and taking full advantage of their knowledge. In this paper, we propose a methodological approach to the design of complex adaptive human-machine systems that might be inclusive of all users, in particular the vulnerable ones. The proposed approach takes into account both the technical requirements and the requirements for ethical, legal and social implications (ELSI) for the design of automatic systems. The technical requirements derive from a thorough analysis of three use cases taken from the European project INCLUSIVE. To achieve the ELSI requirements, the MEESTAR approach is combined with the specific legal issues for occupational systems and requirements of the target users.
2017
- Multi-robot systems implementing complex behaviors under time-varying topologies
[Articolo su rivista]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we address the problem of obtaining complex dynamic behaviors in multi-robot systems. In particular, those complex behaviors are modeled in terms of cooperative tracking of periodic setpoint trajectories. The proposed solution considers a heterogeneous group of robots: a few independent robots are used as a control input for the system, with the aim of controlling the position of the remaining robots, namely the dependent ones. The proposed control strategy explicitly considers changes in the communication topology among the robots, that lead to the definition of a switched system. In particular, these changes happen as the system evolves, since robots are equipped with finite range communication devices. A methodology is introduced for defining the system parameters in order to guarantee asymptotic stability of the switched system, thus guaranteeing the desired tracking performance, assuming that independent robots are able to measure or estimate the global state of the multi-robot system.
2017
- Natural interaction based on affective robotics for multi-robot systems
[Relazione in Atti di Convegno]
Villani, Valeria; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we introduce a novel approach
that enables users to interact with a multi-robot system in a
natural manner. Additionally, interaction adapts to the user’s
affect and stamina. To this end, we consider the use of a
smartwatch for recognizing the motion of the user’s forearm,
which is then translated in velocity commands for the robots.
A natural mapping between user’s movements and robots
commands is implemented, so that the user can intuitively drive
the robots by mimicking real-world behavior. Additionally, the
operator’s heart rate is measured, since it is a measure of mental
stress. Thus, when an increase in mental stress is detected,
the behavior of the multi-robot system is changed in order to
simplify the interaction task and relieve the user. The proposed
interaction system is tested with different users. Specifically,
the effectiveness of the natural interaction is evaluated and
compared to the use of a joypad and a haptic device. Moreover,
we preliminarily test the affective interaction approach.
2017
- Optimized simultaneous conflict-free task assignment and path planning for multi-AGV systems
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Digani, Valerio; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we address the problem of assigning a set of tasks to a set of Automated Guided Vehicles (AGVs), in a conflict-free manner. Specifically, we consider a system of multiple AGVs, moving along a predefined roadmap, and utilized for transportation of goods in automated warehouses. Sequential application of task assignment and path planning often gives rise to pathological situations, such as deadlocks, in which AGVs block each other, thus preventing tasks completion. In this paper we propose a method for assigning tasks while taking into account the subsequent path planning, encoding possible conflicts into a conflict graph, that is subsequently utilized for defining constraints of an optimization problem. Simulations are performed on maps of real industrial environments, to compare the proposed method with traditional task assignment.
2017
- Safe navigation and experimental evaluation of a novel tire workshop assistant robot
[Relazione in Atti di Convegno]
Levratti, Alessio; Riggio, Giuseppe; De Vuono, Antonio; Fantuzzi, Cesare; Secchi, Cristian
abstract
This paper presents TIREBOT, a novel tire-workshop robotic co-worker that can safely move in a tire workshop and assist the operator in lifting and transporting wheels among several working stations. A safe and cooperative navigation strategy based on the concept of danger field is illustrated. Finally, TIREBOT is experimentally evaluated in a real tire-workshop and used by real operator in order to assess the usability and the effectiveness of the robot in a real operating scenario.
2017
- Simulation and Optimisation of Production Lines in the Framework of the IMPROVE Project
[Relazione in Atti di Convegno]
Longo, CLAUDIO SANTO; Fantuzzi, C.
abstract
Simulation is the key technology to enhance the product and production engineering processes. This paper presents an example of application of the simulation to the virtual design and optimization of a industrial production line
2017
- Towards modern inclusive factories: A methodology for the development of smart adaptive human-machine interfaces
[Relazione in Atti di Convegno]
Villani, Valeria; Sabattini, Lorenzo; Czerniaki, Julia N.; Mertens, Alexander; Vogel-Heuser, Birgit; Fantuzzi, Cesare
abstract
Modern manufacturing systems typically require high degrees of flexibility, in terms of ability to customize the production lines to the constantly changing market requests. For this purpose, manufacturing systems are required to be able to cope with changes in the types of products, and in the size of the production batches. As a consequence, the human-machine interfaces (HMIs) are typically very complex, and include a wide range of possible operational modes and commands. This generally implies an unsustainable cognitive workload for the human operators, in addition to a non-negligible training effort. To overcome this issue, in this paper we present a methodology for the design of adaptive human-centred HMIs for industrial machines and robots. The proposed approach relies on three pillars: measurement of user's capabilities, adaptation of the information presented in the HMI, and training of the user. The results expected from the application of the proposed methodology are investigated in terms of increased customization and productivity of manufacturing processes, and wider acceptance of automation technologies. The proposed approach has been devised in the framework of the European project INCLUSIVE.
2017
- Variable admittance control preventing undesired oscillating behaviors in physical human-robot interaction
[Relazione in Atti di Convegno]
Landi, Chiara Talignani; Ferraguti, Federica; Sabattini, Lorenzo; Secchi, Cristian; Bonfe', Marcello; Fantuzzi, Cesare
abstract
Admittance control is a widely used approach for guaranteeing a compliant behavior of the robot in physical human-robot interaction. When an admittance-controlled robot is coupled with a human, the dynamics of the human can cause deviations from the desired behavior of the robot, mainly due to a stiffening of the human arm, and thus generate high-frequency unsafe oscillations of the robot. In this paper we present a novel methodology for detecting the rising oscillations in the human-robot interaction. Furthermore, we propose a passivity-preserving strategy to adapt the parameter of the admittance control in order to get rid of the high-frequency oscillations and, when possible, to restore the desired interaction model. A thorough experimental validation of the proposed strategy is performed on a group of 26 users performing a cooperative task.
2017
- Walk-Through Programming for Industrial Applications
[Articolo su rivista]
Ferraguti, Federica; TALIGNANI LANDI, Chiara; Secchi, Cristian; Nolli, Marco; Pesamosca, Manuel; Fantuzzi, Cesare
abstract
Collaboration between humans and robots is increasingly desired in several application domains, including the manufacturing domain. The paper describes a software control architecture for industrial robotic applications allowing human-robot cooperation during the programming phase of a robotic task. The control architecture is based on admittance control and tool dynamics compensation for implementing walk-through programming and manual guidance. Further steps to integrate this system on a real industrial setup include the robot kinematics and a socket communication that sends a binary file to the robot.
2016
- Catching the wave: A transparency oriented wave based teleoperation architecture
[Relazione in Atti di Convegno]
Secchi, Cristian; Ferraguti, Federica; Fantuzzi, Cesare
abstract
Wave variables are a very popular approach for dealing with communication delay in bilateral teleoperation because of their effectiveness and of their simplicity. Nevertheless, the inherent dynamics of wave based communication channels is often deleterious for the transparency of the teleoperation system. Recently proposed architectures like TDPN, PSPM and two layers approach allow to achieve a high transparency at the price of a complex architecture, with some parameters to tune empirically. In this paper we propose a novel wave based architecture that blends the high performance that can be achieved by recently proposed architectures with the simplicity of wave based bilateral teleoperation.
2016
- Coordinated motion for multi-robot systems under time varying communication topologies
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Lotti, Marco; Fantuzzi, Cesare
abstract
This paper introduces a control strategy for obtaining cooperative tracking of periodic setpoint trajectories in multi-robot systems. A heterogeneous group of robots is considered: a few independent robots are used as a control input for the system, with the aim of controlling the position of the remaining robots, namely the dependent ones. The control strategy presented in this paper explicitly considers changes in the communication topology among the robots. These changes happen as the system evolves, since robots are equipped with finite range communication devices.
2016
- Design of a packaging machine and virtual commissioning via modular hardware-in-the-loop simulations
[Relazione in Atti di Convegno]
Tessari, R.; Fantuzzi, C.
abstract
This paper describes an implementation of a model-based methodology to validate an innovative Hardware-in-the-loop (HIL) scheme applied to a mechatronic modular structure for a packaging machine. This new HIL environment is implemented by means of a unique CPU and allows use of an ordinary personal computer for the HIL simulation of a module of the packaging machine, without any other hardware tool. The research includes identification of modular building blocks through a suitable model-based systems design, with SysML models, Simulink models, and Beckhoff TwinCAT software. The novel HIL scheme is presented accompanied by experimental results of a composite module, which consists of four sub-modules.
2016
- Design of cyber-physical systems: Definition and metamodel for reusable resources
[Relazione in Atti di Convegno]
Barbieri, G.; Fantuzzi, C.
abstract
The utilization of modular and reusable resources would reduce complexity and lead-time for the design of cyber-physical systems. Even if different theories have been proposed, there is not a general definition and metamodel applicable for reusable resources. Energetic approaches constitute the state of the art for modeling the dynamics of physical systems. Within this work, Power-Oriented Graphs energetic approach is adapted to cyber-physical systems in order to provide a definition for reusable resources. Eventually, a metamodel for reusable resources is proposed.
2016
- Design of mechatronic systems through aspect and object-oriented modeling
[Articolo su rivista]
Barbieri, Giacomo; Derler, Patricia; Auslander, David M.; Borsari, Roberto; Fantuzzi, Cesare
abstract
Design of mechatronic systems involves the use of multiple disciplines, from mechanics to electronics and computer science. Different granularities of hybrid co-simulations with increasing details can be used during the design process. However, there is the need of modeling tools for effectively managing the necessary abstraction layers. This work proposes a combination of Aspect-Oriented and Object-Oriented modeling for reaching the goal. Moreover, it shows how the utilization of these tools can facilitate design-space exploration, segregation of domains of expertise and enhances co-design.
2016
- Hierarchical coordination strategy for multi-AGV systems based on dynamic geodesic environment partitioning
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Digani, Valerio; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we consider the problem of coordinating the motion of a group of Automated Guided Vehicles (AGVs) utilized in industrial environments for logistics operations. In particular, we consider a hierarchical coordination strategy, where the environment is partitioned into sectors: coordination on the top layer defines the sequence of sectors to be traveled, while coordination on the bottom layer deals with traffic management inside each sector. In this paper we introduce a novel partitioning algorithm, that defines the sectors in a dynamic manner, taking into account both the shape of the (generally non-convex) environment, and the current distribution of the AGVs. This is achieved exploiting a clustering algorithm, and subsequently defining the sectors based on the geodesic distance.
2016
- Metodo per il trattamento superficiale di un manufatto
[Brevetto]
Fantuzzi, Cesare; Secchi, Cristian; Ferraguti, Federica; TALIGNANI LANDI, Chiara; Noli, Marco
abstract
Secondo la presente invenzione vengono un metodo ed un impianto per il trattamento superficiale secondo quanto licitato nelle rivendicazioni indipendenti che seguono e, preferibilmente, in una qualsiasi delle rivendicazioni dipendenti direttamente o indirettamente dalle rivendicazioni indipendenti.
Nel presente testo per “coppia” si intende “momento di una forza” (torque) o comunque un’altra grandezza contenente il (più precisamente, funzione del) momento di una forza. “Momento di una forza” (o “momento meccanico”) ha il suo comune significato di attitudine di una forza ad imprimere una rotazione ad un corpo rigido attorno ad un punto (nel piano) o ad un asse (nello spazio) quando questa non è applicata al suo centro di massa.
Nel presente testo per “forza” si intende anche (oltre al significato dato normalmente a questo termine) un’altra grandezza contenente la (più precisamente, funzione della) forza. Secondo alcune forme d’attuazione, per “forza” si intende forza secondo il suo normale significato.
2016
- Multi-AGV systems in shared industrial environments: Advanced sensing and control techniques for enhanced safety and improved efficiency
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Cardarelli, Elena; Digani, Valerio; Secchi, Cristian; Fantuzzi, Cesare
abstract
This chapter describes innovative sensing technologies and control techniques that aim at improving the performance of groups of automated guided vehicles (AGVs) used for logistics operations in industrial environments. We explicitly consider the situation where the environment is shared among AGVs, manually driven vehicles, and human operators. In this situation, safety is a major issue that needs always to be guaranteed, while still maximizing the efficiency of the system. This paper describes some of the main achievements of the PAN-Robots European project.
2016
- MyAID: a Troubleshooting Application for Supporting Human Operators in Industrial Environment
[Relazione in Atti di Convegno]
Villani, Valeria; Battilani, Nicola; Lotti, Giulia; Lotti, Giulia; Fantuzzi, Cesare
abstract
Nowadays manufacturing systems are increasing in sophistication and complexity. In this scenario, human operators experience many diffculties to interact effciently with the machine. To tackle this problem, in this paper we present a novel interactive troubleshooting tool to be used in industrial environment. The application, called MyAID, relies on a hypermedia information system and aims at assisting shopoor workers in a factory to perform preventive and corrective machine maintenance. The main advantages of MyAID are the following. First, it overcomes limitations of conventional printed documentation. Second, it can be easily updated and adapted to other machines or uses, other than troubleshooting, since it enjoys a modular structure. Third, it can be connected directly to the control unit of the machine to read active alarms or verify whether the user is following correctly the troubleshooting procedure. Finally, the plan for usability assessment of the proposed application, which is organized in a preliminary heuristic evaluation according to Nielsen's heuristics and field tests with users, is introduced.
2016
- Optimizing the use of power in wave based bilateral teleoperation
[Relazione in Atti di Convegno]
Ferraguti, Federica; Fantuzzi, Cesare; Secchi, Cristian
abstract
Because of their simplicity, wave variables have become almost a standard strategy for stabilizing delayed bilateral teleoperation systems. However, the price to pay for a stable behavior is a degradation in the performance of the teleoperation system. Recently, more flexible and transparency oriented bilateral architectures have been proposed (e.g. TDPN, PSPM, Two-Layer approach) but they are complex to implement and to tune. In [1], a strategy for blending the high performance of the new control methodologies with the simplicity of wave based bilateral teleoperation has been proposed. Nevertheless, while appealing in terms of simplicity, this method is conservative in terms of the transparency that can be achieved. In this paper, we extend the architecture in [1] in order to optimize the use of the energy and for achieving a coupling that is as close as possible to the desired one while preserving the passivity of the overall system.
2016
- Smartwatch-Enhanced Interaction with an Advanced Troubleshooting System for Industrial Machines
[Relazione in Atti di Convegno]
Villani, Valeria; Sabattini, Lorenzo; Battilani, Nicola; Fantuzzi, Cesare
abstract
Smartwatches are unobtrusive everyday devices which can be also exploited for effective gesture-based human-machine interaction. In this paper, we propose the use of a smartwatch to interact with an advanced troubleshooting application to be used in industrial environment. The application is a hypermedia information system aiming at assisting workers in performing preventive and corrective machine maintenance. The smartwatch allows a handsfree interaction, thus facilitating the use of the whole system when wearing personal protective equipment such as gloves or having fingers greased with oil or dust, which prevent operating touch screens. The algorithm for gesture recognition we have devised, which is based on template matching, is described in the paper, together with its experimental validation. Finally, we present a preliminary usability assessment of the overall system, meant as integration of the smartwatch with the hypermedia system.
2016
- TIREBOT: A novel tire workshop assistant robot
[Relazione in Atti di Convegno]
Levratti, Alessio; De Vuono, Antonio; Fantuzzi, Cesare; Secchi, Cristian
abstract
In this paper a novel tire workshop assistant robot is presented. The robot can load heavy wheels and transport them in any place of the workshop, lifting the operator from the effort of doing it manually. The operator can interact with the robot through gestures, which are captured by a RGB-D camera and translated into commands, or teleoperate it through a control station equipped with a haptic interface, which can also return a force feedback. The robot can also operate autonomously with a mission manager that decides where the robot has to go in order to accomplish a certain task. The paper presents a description of the design process and motivations of every design choice.
2016
- Tool Compensation and Force Password Identification on Admittance-Controlled Robots in Walk-Through Programming
[Relazione in Atti di Convegno]
TALIGNANI LANDI, Chiara; Ferraguti, Federica; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper presents an example of a walk-through
programming technique that exploits the payload compensation
to execute the teaching phase of the robot programming.
During this phase the human operator grabs the tool attached
to the end-effector and physically walks the robot through
the desired positions without any effort, since the static and
dynamics effects produced by the tool are compensated. In
the meantime, the robot controller records all the poses and
then it will be able to reproduce the trajectory back. The
addition of a “force password” identification allows to start
and stop the recording in a simple way, disregarding the use of
additional external buttons or software commands. Experiments
are used to validate the proposed control architecture and a pick
and place example is presented, to show a realistic industrial
application.
2016
- Tool Compensation in Walk-Through Programming for Admittance-Controlled Robots
[Relazione in Atti di Convegno]
TALIGNANI LANDI, Chiara; Ferraguti, Federica; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper describes a walk-through programming technique, based on admittance control and tool dynamics compensation, to ease and simplify the process of trajectory learning in common industrial setups. In the walk-through programming, the human operator grabs the tool attached at the robot end-effector and "walks" the robot through the desired positions. During the teaching phase, the robot records the positions and then it will be able to interpolate them to reproduce the trajectory back. In the proposed control architecture, the admittance control allows to provide a compliant behavior during the interaction between the human operator and the robot end-effector, while the algorithm of compensation of the tool dynamics allows to directly use the real tool in the teaching phase. In this way, the setup used for the teaching can directly be the one used for performing the reproduction task. Experiments have been performed to validate the proposed control architecture and a pick and place example has been implemented to show a possible application in the industrial field.
2016
- Value chain vs life cycle approach for product extensions
[Relazione in Atti di Convegno]
Cutrona, G.; Margini, A.; Fantuzzi, C.
abstract
The methodology presented in this paper aims at supporting the whole needs and the Stakeholder Requirements definition in product development or product extension projects. To achieve that goal, the methodology forces to take into account the relevant Stakeholders and the Product Life-Cycle phases they impact on for that product. The paper shows a practical example taken from a real product extension project where the methodology was used. Since the main inputs for product extensions usually come from the marketing department, it resulted to be very effective in broadening the perspective. Thus it ended up in a holistic list of requirements, covering the needs of all the Stakeholders. Requirements frame the development problem, hence, as more they are complete as less failure risks there are. The methodology requires further experiments in other industries to prove its generality. Nonetheless it is expected to provide great support in product extension activities by lowering failure risk and by helping in satisfying all the Stakeholder needs.
2015
- A dynamic routing strategy for the traffic control of AGVs in automatic warehouses
[Relazione in Atti di Convegno]
Secchi, Cristian; Olmi, Roberto; Rocchi, Fabio; Fantuzzi, Cesare
abstract
In this paper we propose a novel algorithm for the dynamic routing of a group of Autonomous Guided Vehicles (AGVs) used for transporting goods in automatic warehouses. Our strategy allows to improve the efficiency of a fleet of AGVs in terms of delivery time and its computational burden is sufficiently small to be embedded in standard industrial traffic management system. The algorithm is validated in a small-scale automatic warehouse with real AGVs.
2015
- A PackML-based design pattern for modular PLC code
[Relazione in Atti di Convegno]
Barbieri, G.; Battilani, N.; Fantuzzi, C.
abstract
Software is exponentially growing in modern automatic machines. Consequently, the operations of writing, debug and maintenance are increasing the time necessary to be accomplished. In order to shorten this time, there is the need to define methodologies for software which enhance modularity, along with re-usability and standardization. This work collects the needs of several industries working in packaging domain for PLC code writing, proposing a solution which overcomes the limits of other well known approaches defined in literature: Object-Orientation and Model Driven Engineering. The proposed solution is a design pattern based on the PackML. This can be considered as an introductory work about this topic. We hope that the scientific community will increase the researches, in order to standardize and facilitate the software writing which dimensions are becoming an issue above all for Small and Medium Enterprises (SMEs).
2015
- Advanced sensing and control techniques for multi AGV systems in shared industrial environments
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Cardarelli, Elena; Digani, Valerio; Secchi, Cristian; Fantuzzi, Cesare; Fuerstenberg, Kay
abstract
This paper describes innovative sensing technologies and control techniques, that aim at improving the performance of groups of Automated Guided Vehicles (AGVs) used for logistics operations in industrial environments. We explicitly consider the situation where the environment is shared among AGVs, manually driven vehicles, and human operators. In this situation, safety is a major issue, that needs always to be guaranteed, while still maximizing the efficiency of the system. This paper describes some of the main achievements of the PAN-Robots European project.
2015
- Cloud robotics paradigm for enhanced navigation of autonomous vehicles in real world industrial applications
[Relazione in Atti di Convegno]
Cardarelli, Elena; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
Autonomous vehicles require advances sensing technologies, in order to be able to safely share the environment with human operators. Those sensing technologies are in fact necessary for identifying the presence of unforeseen objects, and measuring their position and velocity. Furthermore, classification is necessary for effectively predicting their behavior. In this paper we consider the presence of sensing systems both on-board each vehicle, and installed on infrastructural elements. While the simultaneous presence of multiple sources of information heavily improves the amount (and quality) of available data, it generates the need for effective data fusion and storage systems. Hence, we introduce a centralized cloud service, that is in charge of receiving and merging data acquired by different sensing systems. Those data are then distributed to the autonomous vehicles, that exploit them for implementing advanced navigation strategies. The proposed methodology is validated in a real industrial environment to safely perform obstacle avoidance with an autonomously driven forklift.
2015
- Conducting multi-robot systems: Gestures for the passive teleoperation of multiple slaves
[Relazione in Atti di Convegno]
Secchi, Cristian; Sabattini, Lorenzo; Fantuzzi, Cesare
abstract
When teleoperating a multi-robot system it is useful to control the kind of behavior of the fleet depending on the environment it is moving in. In this paper, a novel bilateral control architecture for teleoperating a group of mobile robots is proposed. The user can command the robots both as a flexible and amorphous group and as a set of agents executing different trajectories for achieving a desired task, mimicking a conductor-orchestra paradigm. Exploiting passivity based control, we ensure a stable and safe behavior for the user. The proposed teleoperation strategy is validated by means of experiments.
2015
- Coordinated dynamic behaviors in multi-robot systems with time-varying topologies
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Levratti, Alessio; Cocetti, Matteo; Fantuzzi, Cesare
abstract
A control strategy for the execution of coordinated complex dynamic behaviors in multi-robot systems is introduced in this paper. In particular, considering a dependent-independent robot partitioning of a multi-robot system, we introduce a methodology for controlling the independent robots in such a way that, exploiting local interaction, the dependent robots are driven to track desired periodic setpoint trajectories. The control strategy is designed taking explicitly into account variations in the interconnection topology, due to relative movements among the robots.
2015
- Decentralized Control of Cooperative Robotic Systems for Arbitrary Setpoint Tracking while Avoiding Collisions
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Levratti, Alessio; Fantuzzi, Cesare
abstract
Decentralized control strategies for multi-robot systems have been extensively studied in the literature, with the aim of regulating the overall state of the system to some desired configuration. Recently a few works have appeared that propose methodologies for solving more complex problems: in particular, partitioning of the multi-robot system into two subgroups can be exploited for cooperatively tracking arbitrarily defined setpoint functions. Specifically, a small number of independent robots can be exploited for controlling the overall state of the dependent robots. Based on this formulation, in this paper we exploit the null space based behavioral approach to obtain setpoint tracking for a multi-robot system, while avoiding inter-robot collisions.
2015
- Edge-Weighted Consensus Based Formation Control Strategy With Collision Avoidance
[Articolo su rivista]
Falconi, R.; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare; Melchiorri, C.
abstract
In this paper, a consensus-based control strategy is presented to gather formation for a group of differential-wheeled robots. The for- mation shape and the avoidance of collisions between robots are ob- tained by exploiting the properties of weighted graphs. Since mobile robots are supposed to move in unknown environments, the presented approach to multi-robot coordination has been extended in order to include obstacle avoidance. The effectiveness of the proposed control strategy has been demonstrated by means of analytical proofs. More- over, results of simulations and experiments on real robots are provided for validation purposes.
2015
- Eigenvalue placement for asymptotic stability in piecewise linear switched systems
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we provide an eigenvalue placement methodology that guarantees asymptotic stability in a piecewise linear switched system where a lowerbound on the dwell time is known in advance. In particular, considering the case where each subsystem is a linear controllable system, we introduce an algorithm for placing the eigenvalues of each subsystem in such a way that the overall switched system is asymptotically stable. This is obtained defining a relationship between the dwell time and the stability properties of each subsystem. Simulations of a heterogeneous multi-robot system are provided for validation purposes.
2015
- Ensemble Coordination Approach in Multi-AGV Systems Applied to Industrial Warehouses
[Articolo su rivista]
Digani, Valerio; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper deals with a holistic approach to coordinate a fleet of automated guided vehicles (AGVs) in an industrial environment. We propose an ensemble approach based on a two layer control architecture and on an automatic algorithm for the definition of the roadmap. The roadmap is built by considering the path planning algorithm implemented on the hierarchical architecture and vice versa. In this way, we want to manage the coordination of the whole system in order to increase the flexibility and the global efficiency. Furthermore, the roadmap is computed in order to maximize the redundancy, the coverage and the connectivity. The architecture is composed of two layers. The low-level represents the roadmap itself. The high-level describes the topological relationship among different areas of the environment. The path planning algorithm works on both these levels and the subsequent coordination among AGVs is obtained exploiting shared resource (i.e., centralized information) and local negotiation (i.e., decentralized coordination). The proposed approach is validated by means of simulations and comparison using real plants.
2015
- Fault diagnosis in a power plant using artificial neural networks: Analysis and comparison
[Relazione in Atti di Convegno]
Simani, S.; Marangon, F.; Fantuzzi, C.
abstract
In this paper a model-based procedure exploiting analytical redundancy via state estimation techniques for the diagnosis of faults regarding sensors of a dynamic system is presented. Fault detection is based on Kalman filters designed in stochastic environment. Such a design is enhanced by processing the noisy data according to the Frisch Scheme identification method. Fault diagnosis is performed by means of different neural network architectures. In particular, neural networks are used as function approximators to estimate single sensor fault size. The proposed fault diagnosis tool is tested on a power plant. Results from simulation are compared with the ones obtained in some related works.
2015
- Generating automatically the documentation from PLC code by D4T3 to improve the usability and life cycle management of software in automation
[Relazione in Atti di Convegno]
Racchetti, L.; Tacconi, L.; Fantuzzi, C.
abstract
D4T3 (i.e. Doxygen for TwinCAT3) was developed to generate automatically the documentation from a set of documented and/or undocumented PLC source files. D4T3 documentation was designed to support traditional PLC-world features (e.g. inputs, programs, tasks, etc.) and more recent Object Oriented features of IEC61131-3 (e.g. interfaces, inheritance, etc.). Moreover, this documentation was designed to be generated as an on-line manual (i.e. HTML) and/or as an off-line reference manual (e.g. LATEX, CHM, etc.). The usability, maintainability and understanding of documented PLC software was found significantly improved when the software was provided with its D4T3 documentation. Additionally, D4T3 reduced the time spent on documentation and managed the differences among versions. Thus, the automated documentation generator can be used to simplify/overcome the usability and life-cycle-management challenges in automation. It can also lead PLC vendors to design a common tool to generate the PLC software documentation supporting system engineers and software engineers in automation.
2015
- Implementation of Coordinated Complex Dynamic Behaviors in Multirobot Systems
[Articolo su rivista]
Sabattini, Lorenzo; Secchi, Cristian; Cocetti, Matteo; Levratti, Alessio; Fantuzzi, Cesare
abstract
Decentralized control strategies for multirobot systems have been extensively studied over the past few years. Typically, these strategies aim at exploiting local interaction rules to regulate the overall state of the multirobot system toward a desired configuration, thus generating some desired coordinated behaviors, such as synchronization, swarming, deployment, or formation control. However, when considering the real-world application of multirobot systems, more complex cooperative dynamic behaviors are desirable. Along these lines, in this paper, we propose a methodology to control a multirobot system for cooperatively tracking arbitrarily defined periodic setpoint trajectories. This objective is fulfilled partitioning the multirobot system into independent robots (that can provide control inputs) and dependent robots (that are controlled through local interaction). The motion of the independent robots is then defined in such a way that, exploiting local interactions, the dependent robots are controlled to track the desired trajectories. The proposed control strategy is validated by means of simulations and experiments on real robots.
2015
- Improving AGV systems: Integration of advanced sensing and control technologies
[Relazione in Atti di Convegno]
Oleari, Fabio; Magnani, Massimiliano; Ronzoni, Davide; Sabattini, Lorenzo; Cardarelli, Elena; Digani, Valerio; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper focuses on the integration of advanced sensing and control technologies into advanced systems of multiple Automated Guided Vehicles (AGVs). In particular, we focus on the key technologies developed within the Plug-and-Navigate Robots (PAN-Robots) project, highlighting how those results contribute to improving the performance of AGV systems.
2015
- Interacting with a multi AGV system
[Relazione in Atti di Convegno]
Cardarelli, Elena; Sabattini, Lorenzo; Digani, Valerio; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper introduces a novel Human Machine Interface (HMI) that allows users to interact with a fleet of Automated Guided Vehicles (AGVs) used for logistics operations in industrial environments. The interface is developed for providing operators with information regarding the fleet of AGVs, and the status of the industrial environment. Information is provided in an intuitive manner, utilizing a three-dimensional representation of the elements in the environment. The HMI also allows operators to influence the behavior of the fleet of AGVs, manually inserting missions to be accomplished.
2015
- Mission Assignment for Multi-Vehicle Systems in Industrial Environments
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Digani, Valerio; Lucchi, Matteo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we introduce a methodology for mission assignment in multiple vehicle system exploited in industrial environments for logistics operations. We explicitly consider the model of the traffic, for performing an optimized dynamic mission assignment. Simulation results are provided for comparing the proposed methodology with state-of-the-art techniques, that do not consider the state of the traffic while allocating missions.
2015
- Modelling and simulation for the integrated design of mechatronic systems
[Relazione in Atti di Convegno]
Barbieri, G.; Goldoni, G.; Borsari, R.; Fantuzzi, C.
abstract
The development of mechatronic systems involves the use of multiple disciplines, from mechanical engineering to electronics engineering and computer science. Traditionally, every discipline was developed independently and then integrated to generate the final system. However, high quality designs cannot be achieved without simultaneously considering all the engineering disciplines. This mechatronic approach carries intrinsic complexity into system design process and numerous researches are on-going in order to find out optimal methods. This article refines a SysML-based design process for the high level development of mechatronic systems, focusing on the integration of modelling and simulation as fundamental aspect for an integrated approach. How conceptual SysML diagrams may support the generation of simulation models is shown, along with a chain of simulations for an integrated design. The proposed approach is applied to a prototype case study designed from scratch, in order to be validated and to demonstrate its potentiality.
2015
- Overcoming real time bond in high level simulation environments
[Relazione in Atti di Convegno]
Panciroli, Roberto; Torelli, Carlo; Barbieri, Giacomo; Borsari, Roberto; Fantuzzi, Cesare
abstract
Overcoming Real Time Bond in High Level Simulation Environments
2015
- Port-Hamiltonian based teleoperation of a multi-robot system on periodic trajectories
[Relazione in Atti di Convegno]
Secchi, Cristian; Sabattini, Lorenzo; Fantuzzi, Cesare
abstract
In this paper, we exploit port-Hamiltonian systems for building a novel teleoperation
architecture for a group of mobile agents that need to track a set of prede_ned trajectories.
Using port-Hamiltonian system we can guarantee an intrinsically safe and passive bilateral
teleoperation system while using linear regulation system we can ensure an asymptotic
tracking. The performance of the teleoperation system are evaluated by means of
experiments.
2015
- Product Service System Design: How to Design Humans Application of a methodology in a PSS development with high human involvement
[Articolo su rivista]
Margini, Andrea; Cutrona, Gaetano; Fantuzzi, Cesare
abstract
A three-step methodology is proposed to support development teams in product-service system (PSS) development projects. The methodology specifically addresses the problem of designing humans as part of the system. The human presence is a matter of fact when it comes to PSSs. They are the soft system delivering the service part of the PSS, which is also the most value adding for stakeholders. Furthermore many manufacturing companies are moving towards the integration of products and services. There are many structured approaches to support the design of software and tangible objects, i.e. the hard system. However there is a lack of guidance when it comes to the human presence design and integration with the hard system. The methodology aims at filling this gap. It was validated in a PSS development project within a company with a strong focus in product development. Hence it had to fit to an already in place product development framework. The findings were used to further refine the methodology. The methodology was fully applicable within that specific framework. However further validation runs are necessary to ensure its generality. The methodology will support the shift from pure manufacturer to product-service deliverer for those companies willing to change the rules of competition and to deliver more value to their customers.
2015
- Structured product development process implementation for a packaging company
[Relazione in Atti di Convegno]
Margini, A.; Cutrona, G.; Fantuzzi, C.
abstract
This paper describes the analysis of a structured development process (SDP) that takes into account the particular specifications and requirements in the manufacture of packaging machines. The proposed approach is based on the well known "V-model" approach, which aims to support engineering teams in developing complex systems.
2015
- The two-machine one-buffer continuous time model with restart policy
[Articolo su rivista]
Gebennini, Elisa; Grassi, Andrea; Fantuzzi, Cesare
abstract
This paper deals with the performance evaluation of production lines in which well defined machine start/stop control policies are applied.
A modeling approach has been developed in order to reduce the complexity of a two-machine one-buffer line where a specific control policy, called “restart policy”, is adopted. The restart policy exercises control over the start/stop condition of the first machine: when the buffer gets full and, as a consequence, the first machine is forced to stop production (i.e., it is blocked), the control policy keeps the first machine in an idle state until the buffer becomes empty again. The rationale behind this policy is to reduce the blocking frequency of the first machine, i.e. the probability that a blockage occurs on the first machine due to the buffer filling up. Such a control policy is adopted in practice when outage costs (e.g., waste production) are related to each restart of the machine.
The two-machine one-buffer line with restart policy (RP line) is here modeled as a continuous time Markov process so as to consider machines having different capacities and working in an asynchronous manner. The mathematical RP model is described along with its analytical solution. Then, the most critical line performance measures are derived and, finally, some numerical examples are reported to show the effects of such a policy on the blocking frequency of the first machine.
2015
- Towards an abstraction layer for PLC programming using object-oriented features of IEC61131-3 applied to motion control
[Relazione in Atti di Convegno]
Racchetti, L.; Fantuzzi, C.; Tacconi, L.; Bonfe, M.
abstract
We present our Abstraction Layer Object-oriented Architecture (ALOOA) and its application to Motion Control. This layer provides a higher level of abstraction than that provided by the well-known PLCOpen library. In fact, the proposed approach uses OO features (i.e. methods, inheritance, and polymorphism) which allow us to define a generic device of motion control, whose hardware-dependent implementation details are then developed with specific Function Blocks (FBs) and methods. We are currently developing and using in our software the ALOOA and its libraries. As result, we can create hardware-independent software applications. Additionally, we achieved a reuse degree of our code of about 70% and improved its maintainability. ALOOA approach could be used to simplify and/or fulfill the maintainability, life-cycle-management, and the specific-platforms-and-their-limitations challenges. Moreover, it could help the OO features to penetrate further into the PLC world.
2015
- Verification and Validation based on the generation of Testing Sequences from Timing Diagram Specifications in Industrial Automation
[Relazione in Atti di Convegno]
Racchetti, L; Fantuzzi, C; Tacconi, L
abstract
We present Timing Diagram Testing for Verification & Validation (T4V, which is red as "tav") for Industrial Automation Systems. T4V is our approach to address the problem of generating test sequence to verify & validate (V&V) industrial automation systems software.T4V aims to solve this problem by generating test sequences from the timing diagrams of software specifications. Then, run them in Real-Time (RT) onto the PLC, check part of their conformance on-the-run, save the test outlines, and automatically analyze the outlines through an algorithmic verification.We currently implemented T4V for IEC61131-3 platforms (e.g. Beckhoff TwinCAT3) and Rockwell Automation PLCs, but we are integrating it only in our testing and V&V platform for Beckhoff PLCs.We believe that T4V may simplify and/or face the challenges of V&V in order to enable a more efficient and effective testing. Moreover, we believe that it could help PLC providers to understand the needs of an environment with testing and V&V features integrated.
2014
- A model-based design methodology for the development of mechatronic systems
[Articolo su rivista]
Fantuzzi, Cesare; Barbieri, Giacomo; Borsari, Roberto
abstract
The development of mechatronic systems involves the use of multiple disciplines, from mechanical engineering to electronics engineering and computer science.
Traditionally, every discipline was developed independently and then integrated to generate the final system. However, high-quality designs cannot be achieved without simultaneously considering all the engineering disciplines. This integrated approach carries an intrinsic complexity into system design process and numerous researches are on-going in order to find out optimal methods. This article illustrates a methodology based on Model-Based System Engineering to support the integrated development of complex mechatronic devices. The main contribution is the introduction of a design methodology based on the W model and the identification of SysML as the tool to support the whole process.
This method will also address the problem of “devices interchangeability”, that means the possibility to develop the functionality of a system with different operation principles, at a very early stage of the development process (i.e. during the conceptual development). To achieve this goal, the methodology treats the problem of linking the conceptual with executable models to enable the validation by simulation.
Main advantages of this methodology are in providing, to the mechatronic systems designers, a fixed schedule which does not limit their intuition and reduces complexity through a hierarchical approach. The process has been tested through the rationalization of the choices that have brought to the current solution of the filling system of an automatic filling machine for liquid foodstuff.
2014
- A SysML Based Design Pattern for the High-Level Development of Mechatronic Systems to Enhance Re-Usability
[Relazione in Atti di Convegno]
Barbieri, Giacomo; Kernschmidt, Konstantin; Fantuzzi, Cesare; Vogel Heuser, Birgit
abstract
Model driven engineering approaches can be used to handle the complexity in the development of modern mechatronic systems, containing a multitude of mechanical, electrical/electronic and software components. However, up to now SysML, as standard systems engineering language, is not wide spread in industry yet. Reasons therefore are missing adequate guidelines for the modeling process as well as an unclear benefit of the created SysML-models. A well-created system model however poses enormous time advantages during the analysis of change influences in later lifecycle phases of the system and makes an interdisciplinary reuse of modules in the development of new systems possible. A prerequisite therefore is the efficient traceability of all information within the system model. Thus, in this paper a SysML based process for the high-level development of mechatronic systems is applied, reaching from requirements specification to the detailed modeling of the element-connections (discipline specific as well as interdisciplinary). Our approach shows how the information from the different levels of abstraction and the different development phases can be connected, including a functional modularization of the mechatronic system. In this way, developers can trace change influences more easily. The functional modules can be used during the development of new systems, resulting in significant shortened development cycles. The proposed design pattern is shown at the example of a bench-scale model of a production plant.
2014
- An automatic approach for the generation of the roadmap for multi-AGV systems in an industrial environment
[Relazione in Atti di Convegno]
Digani, Valerio; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper deals with the automatic generation of a
roadmap. We propose an approach to build a roadmap
for Automated Guided Vehicles (AGVs) used for
logistics operations in industrial environments. The
algorithm computes a roadmap in such a way that the
coverage, the connectivity and the redundancy of the
paths are maximized. In this way the flexibility and
the efficiency of the AGV system can be
increased. The proposed approach is validated by
means of comparison with different roadmaps manually
built in real plants
2014
- Controllability and Observability Preservation for Networked Systems with Time Varying Topologies
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Fantuzzi, Cesare; Secchi, Cristian
abstract
When dealing with networked systems, the concept of
controllability refers to the possibility of
controlling the overall state of a group of agents
by providing an external input only to a subset of
them, that are referred to as leaders. On the same
lines, the concept of observability is related to
the possibility of observing the whole state of the
networked system from only a subset of the
agents. In this paper we introduce a decentralized
interaction rule that ensures preservation of the
controllability and observability properties of a
networked system. The proposed strategy is based on
the fact that these properties are strongly related
to the topology of the underlying communication
graph. We will show that connectivity maintenance
and a random choice of the edge-weights are key
concepts to ensure controllability and observability
preservation for a networked system
2014
- Cooperative dynamic behaviors in networked systems with decentralized state estimation
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
Networked systems and decentralized control strategies
have been widely investigated in the literature,
with the objective of obtaining coordinated emerging
behaviors by means of local interaction. While
typical approaches aim at solving regulation
problems (e.g. synchronization, swarming, coverage,
formation control) a few works have recently
appeared that move towards the solution of more
complex problems, such as tracking of arbitrary
setpoint functions. Based on the formulation
introduced in [1], this objective is obtained in
this paper partitioning the networked systems into
leaders (that can provide control inputs) and
followers (that are controlled through local
interaction). In this paper we provide a methodology
for letting the leaders estimate the state of the
followers in a decentralized manner: this estimate
is then used for control purposes. Simulations are
provided for validating the proposed control
strategy
2014
- Hierarchical traffic control for partially decentralized coordination of multi AGV systems in industrial environments
[Relazione in Atti di Convegno]
Digani, Valerio; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper deals with decentralized coordination of
Automated Guided Vehicles (AGVs). We propose a
hierarchical traffic control algorithm, that
implements path planning on a two layer
architecture. The high-level layer describes the
topological relationships among different areas of
the environment. In the low-level layer, each area
includes a set of fixed routes, along which the AGVs
have to move. An algorithm is also introduced for
the automatic definition of the route map
itself. The coordination among the AGVs is obtained
exploiting shared resources (i.e. centralized
information) and local negotiation
(i.e. decentralized coordination). The proposed
strategy is validated by means of simulations using
real plant
2014
- Implementation of arbitrary periodic dynamic behaviors in networked systems
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Cocetti, Matteo; Fantuzzi, Cesare
abstract
Decentralized control of networked systems has been
widely investigated in the literature, with the aim
of regulating the overall state of the system to
some desired configuration, thus obtaining
coordinated emerging behaviors
(e.g. synchronization, swarming, coverage, formation
control) by means of local interaction. In this
paper we introduce a methodology to solve a tracking
problem, that is defining a decentralized control
strategy for making a networked system follow an
arbitrarily defined periodic setpoint function. The
most suitable interconnection topology is defined
together with the control law as the solution of a
constrained optimization problem, in order to ensure
asymptotic tracking. Simulations are provided for
validating the proposed control strategy
2014
- Multisensor data fusion for obstacle detection in automated factory logistics
[Relazione in Atti di Convegno]
Cardarelli, Elena; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper describes data fusion methodologies for obstacle
detection in an automation system based on advanced
Automatic Guided Vehicles (AGV), used for automated
logistics in modern factories. We present the
background of the problem, introducing generic
aspects of the system architecture designed to cope
with the obstacle detection in automated factory
logistics; then, we focus on the system
specification for the module responsible of
integrating data from different sources and
providing a global representation of the
environment. Finally, we present a comparative
analysis among different strategies of multisensor
data fusion compliant with the requirements of the
described system, highlighting their advantages and
drawbacks
2014
- Obstacle avoidance for industrial AGVs
[Relazione in Atti di Convegno]
Digani, Valerio; Caramaschi, Fabrizio; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
IEEE International Conference
2014
- Product architecture management - An approach to product life cycle
[Relazione in Atti di Convegno]
Cutrona, G.; Margini, A.; Fantuzzi, C.
abstract
Today a lot of small, medium and also large companies have a project organizational setup. This means that the major part of the development activities are gathered thru the conduction of a project that at its completion will deliver a new version of the product. In this situation managing versions and resources for some of the product components (subsystems) could be a problem or performed in a non efficient way. This paper shows the approach applied in a company producing machines for the food industry. The methodology is based on the application of PLC (Product Life Cycle) principles aiming at the rationalization of the decisions made during the planning, analysis and implementation phases. The goal of the approach is to help designers and product architects to correlate the needs of projects stakeholders (requirements) with other needs related to the product strategy and roadmap in order to improve efficiency in terms of resource management, product variants and other aspects that affect the life cycle of the product.
2014
- The PLC UML State-chart design pattern
[Relazione in Atti di Convegno]
Racchetti, Lorenzo; Fantuzzi, Cesare; Tacconi, Lorenzo; Bonfe, Marcello
abstract
We developed an UML-State-charts Object Oriented Design
Pattern for PLCs IEC61131-3. This PLC
UML-State-chart Design Pattern aims to explore the
advantage of Object Oriented Programming by
IEC61131-3 in PLCs, and to provide a direct map of
UML State-chart to PLC code. We illustrates the
design pattern and its use through UML Class
diagrams and an application example. This Design
Pattern can be used to reduce the development time
of State-charts in automation software. It can also
lead towards further investigations in PLC Design
Patterns that may improve the whole development of
automation software
2014
- TRAFCON – Traffic Control of AGVs in Automatic Warehouses
[Capitolo/Saggio]
Secchi, Cristian; Olmi, R.; Fantuzzi, Cesare; Casarini,
abstract
In this chapter we illustrated the main results of the TRAF- CON experiment. We propose a novel traffic manager for AGVs moving in an automatic warehouse and its experimental validation on simulated real plants and on a small-scale automatic warehouse.
2013
- A low cost localization algorithm for an autonomous lawnmower
[Relazione in Atti di Convegno]
Levratti, Alessio; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper aims at implementing a localization algorithm, based on a Kalman filter, in order to localize an autonomous lawnmower which operates in an outdoor environment using only low cost sensors. In particular the position and the orientation of the robot are estimated using an IMU (Inertial Measurement Unit), an RFID (Radio Frequency IDentification) antenna and an RFID reader (which reads the presence of RFID tags scattered on the border of the lawn to be mowed) and a Wifi antenna, on-board the robot, which measures the RSSI (Received Signal Strength Indicator) of the signal sent by other Wifi end devices positioned in the working area in known positions. The efficiency of the proposed algorithm is then tested first through simulations and then experimentally on a prototype lawnmower.
2013
- A Tank-Based Approach to Impedance Control with Variable Stiffness
[Relazione in Atti di Convegno]
Ferraguti, Federica; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper, we present a new impedance control strategy that allows to reproduce a time-varying stiffness. By properly controlling the energy exchanged during the action, we guarantee the system passivity for any choice of the stiffness matrix, especially in case of time-varying stiffness, and therefore a stable behavior of the robot both in free motion and in interaction with an environment.
A possible application of the presented algorithm is the reproduction of surgeon’s behavior during a puncturing task. In this application, the stiffness is changed depending on the layer of the human body the needle is crossing.
To demonstrate the validity of the proposed method we conducted several simulations. Then, in order to prove the effec- tive useless of the proposed strategy, we built an experimental setup reproducing the puncturing scenario and implemented the algorithm by means of a 7 degree of freedom (DOF) robot manipulator.
2013
- Analytical modeling of series-parallel flow lines
[Relazione in Atti di Convegno]
Gebennini, Elisa; Grassi, Andrea; Fantuzzi, Cesare
abstract
The paper deals with the analytical modeling of series-parallel flow lines, modeled as a continuous time,
mixed state Markov process. Machines are assumed to be unreliable with operation dependent failures;
failure and repair times are assumed to be independent and exponentially distributed.
The methodology to treat such a complex system approximates a parallel-machine stage of the original
flow line as an equivalent unreliable machine. Such a technique has been originally proposed by Burman
(1995). Nevertheless, the results were not enough accurate in several scenarios. Hence, the work presented
in this paper significantly extends the technique proposed by Burman (1995) by describing an iterative
procedure for computing the parameters of the equivalent machine with a higher accuracy. Specifically, the
solution is here provided for the case where the machines of a certain parallel-machine stage are identical.
Once the equivalent machine of each parallel-machine stage has been characterized, the original series-
parallel flow line can be analyzed as a simpler serial flow line, extensively discussed in previous literature.
Finally, a numerical experimentation is discussed to point out some interesting considerations.
2013
- Closed-Curve Trajectory Tracking for Decentralized Systems of Multiple Mobile Robots
[Articolo su rivista]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we address the problem of making a group of mobile robots cooperatively track an assigned path. We consider paths described by com- pletely arbitrarily shaped closed curves. The proposed control strategy is a fully decentralized algorithm and it does not require any global synchronization. The desired behavior is obtained by means of some properly designed artificial poten- tial functions. Analytical proofs are provided to show the asymptotic convergence of the system to the desired behavior. Matlab simulations and experiments on real robots are described as well for validation purposes.
2013
- Collision Avoidance Using Gyroscopic Forces for Cooperative Lagrangian Dynamical Systems
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we introduce a collision avoidance control strategy for groups of mobile robots moving in a three-dimensional environment, whose dynamics are described according to the Lagrangian model. The proposed strategy is based on the use of gyroscopic forces, that ensure obstacle avoidance without interfering with the convergence properties of the multi-robot system's desired control law. Moreover, we introduce a method to define the direction of the force in an optimal way, in order to introduce the smallest possible perturbation with respect to the desired behavior of the system. Collision avoidance and convergence properties are analytically demonstrated, and simulation results are provided for validation purpose.
2013
- Decentralized Control Strategy for the Implementation of Cooperative Dynamic Behaviors in Networked Systems
[Relazione in Atti di Convegno]
M., Cocetti; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
Decentralized control of networked systems has been widely investigated in the literature, with the aim of obtaining coordinated emerging behaviors (e.g. synchronization, swarming, coverage, formation control) by means of local interaction. In this paper we consider the possibility of injecting external inputs into the networked system, in order to obtain more complex cooperative behaviors. Specifically, we introduce a strategy that makes it possible to control the overall state of the networked system by directly controlling only a subset of the networked agents, namely the leaders. Exploiting local interaction rules, it is possible to define the inputs for the leaders in such a way that each follower is forced to track a desired periodic setpoint.
2013
- Decentralized Global Connectivity Maintenance for Interconnected Lagrangian Systems in the Presence of Data Corruption
[Articolo su rivista]
Secchi, Cristian; Sabattini, Lorenzo; Fantuzzi, Cesare
abstract
In order to accomplish cooperative tasks, multi-robot systems are required to communicate among each other. Thus, maintaining the connectivity of the communication graph is a fundamental issue. In this paper we develop a strategy based on Sabattini et al., Decentralized Connectivity Maintenance for Networked Lagrangian Dynamical Systems, 2012 for guaranteeing connectivity in the presence of data corruption. In fact, when dealing with real systems, several sources of data corruption can appear. For instance, sensor noise is one of the primary sources of data corruption. Moreover, when dealing with interconnected robotic systems, assuming instantaneous exchange of data is often unrealistic: com- munication delays are then another important source of data corruption. For this reason, we provide a solution to the connectivity maintenance problem for interconnected Lagrangian dynamical agents, in the presence of data corruption.
2013
- Design Patterns for Model-Based Automation Software Design and Implementation
[Articolo su rivista]
M., Bonfé; Fantuzzi, Cesare; Secchi, Cristian
abstract
The paper presents the application of object-oriented modeling techniques to control software development for complex manufacturing systems, with particular focus on case studies taken from the packaging industry and designpatterns that can be abstracted from such case studies. The proposed methodology for control software modeling and implementation is based on a practical approach refined on the basis of on-the-field experience and interactions with control engineers involved in the development projects.The final objective of the paper is to review and analyze patterns for the solution of design and implementation issues that typically arise in the considered application domain.
2013
- Discrete time model for two-machine one-buffer transfer lines with restart policy
[Articolo su rivista]
Gebennini, Elisa; Grassi, Andrea; Fantuzzi, Cesare; S. B., Gershwin; I. C., Schick
abstract
The paper deals with analytical modeling of transfer lines consisting of two machines decoupled by one finite buffer. In particular, the case in which a control policy (referred as "restart policy") aiming to reduce the blocking frequency of the first machine is addressed. Such a policy consists of forcing the first machine to remain idle (it cannot process parts) each time the buffer gets full until it empties again. This specific behavior can be found in a number of industrial production systems, especially when some machines are affected by outage costs when stops occur. The two-machine one-buffer line is here modeled as a discrete time markov process and the two machines are characterized by the same production rate. The analytical solution of the model is obtained and mathematical expressions of the most important performance measures are provided. Some significant remarks about the effect of the proposed restart policy on the behavior of the system are also pointed out.
2013
- Hardware in the loop simulation and Machine Modular Development: Concepts and application
[Relazione in Atti di Convegno]
Racchetti, L.; Fantuzzi, C.
abstract
Hardware-in-the-Loop (HIL) is an important strategy to test a control system on a model of the real plant. This is particular important in the engineering process related to machine development since it permit to save many resources wasted in the development of a real experiment. This paper discusses how the modular approach in system development (Machine Modular Development, MMD), can support the system engineer (SE) to deal with system complexity in achieving a good HIL structure for validating the automation software. © 2013 IEEE.
2013
- Possibilities and challenges of an integrated development using a combined SysML-model and corresponding domain specific models
[Relazione in Atti di Convegno]
Kernschmidt, K.; Barbieri, G.; Fantuzzi, C.; Vogel-Heuser, B.
abstract
The development of a production plant, with multiple involved disciplines, requires many different models such as simulation models for the physical domain or models of the control-software. As all these models represent parts of the same system, it is inefficient to develop every model from scratch. Rather an integrated model, which considers all relevant aspects, should be set up first and from this the required domain specific models should be generated through model transformations. For the integrated model, the Systems Modeling Language (SysML) poses a suitable possibility to integrate the views of the different disciplines. Based on a literature research, existing model transformations from the integrated model to specific models as well as necessary extensions are presented. In this way a framework for an integrated development, where the SysML-model forms the integrating core model of the system, while the simulation of the different parts is carried out in domain specific simulation tools, can be established. Core benefits of this method are the consistency of the models, and the fast and cost-efficient simulation and testing of the system at different points of the development cycle and with different levels of detail. © IFAC.
2013
- Time critical wireless data transmission in autonomous control applications
[Relazione in Atti di Convegno]
Bliznuks, D.; Univ, Riga T. e. c. h.; Riga, Latvia; Zagurskis, V.; Fantuzzi, Cesare
abstract
The following paper examines problems in fast wireless data acquisition and proposes solution. The paper examines the area of autonomously controlled vehicles. Necessity of well-timed data in such an application is vital, since moving vehicle could damage itself and surroundings. As an example of such a task, authors use recent FP7 project - STRATOS. Existing solutions do not fulfill node amount and frequency requirements of the application. Solution contains all components, transmission technology, media access algorithm and gateway design. The key element for reaching requirements is using parallel data transmissions, along with time division media access (TDMA) algorithm. Testing and simulation proved that designed wireless sensor network that is capable of delivering measurements from 140 sensors with a frequency of 300Hz.
2013
- Tools for the development of a design methodology for mechatronic systems
[Relazione in Atti di Convegno]
Barbieri, Giacomo; Fantuzzi, Cesare; Borsari, Roberto
abstract
Tools for the Development of a Design Methodology for Mechatronic Systems.
2013
- Towards decentralized coordination of multi robot systems in industrial environments: A hierarchical traffic control strategy
[Relazione in Atti di Convegno]
Digani, Valerio; Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper describes an innovative approach to manage multiple Automated Guided Vehicles (AGVs) in an industrial environment. The proposed approach is based on a two layer architecture for path planning. This architecture consists of a topological layer, composed by macro-cells, and of a route map layer in which the AGVs have to move along fixed paths. The traffic is managed in a decentralized manner. Each AGV computes autonomously its own path both at topological layer and at route map layer. The coordination among the AGVs is based on the negotiation of shared resources. An early phase of validation is provided by the simulation in a structured environment.
2012
- A Novel Inertial/RFID Based Localization Method for Autonomous Lawnmowers
[Relazione in Atti di Convegno]
Levratti, Alessio; Bonaiuti, Matteo; Secchi, Cristian; Fantuzzi, Cesare
abstract
Robotic lawnmowers currently available in the market cover their assigned area using a random reflection navigation strategy. While this strategy has been widely accepted for autonomous vacuum cleaning systems, it poses quality problems in outdoor applications since a randomic crossing of the garden can lead to an uneven mowing. In this paper we propose a localization algorithm based on a modified Constrained Kalman Filter that allows to implement an efficient navigation strategy and to increase the quality of service of the mower. This method properly merges data coming from an Inertial Measurement Unit (IMU) and from an RFID (Radio-Frequency IDentification) antenna with information given by the Hall sensors of the wheels of the robot. The proposed algorithm has been verified first by simulation, and then with experiments by building a prototype lawnmower robot.
2012
- An algorithm to diagnose ball bearing faults in servomotors running arbitrary motion profiles
[Articolo su rivista]
Cocconcelli, Marco; L., Bassi; Secchi, Cristian; Fantuzzi, Cesare; Rubini, Riccardo
abstract
This paper describes a procedure to extend the scope of classical methods to detectball bearing faults (based on envelope analysis and fault frequencies identification)beyond their usual area of application. The objective of this procedure is to allowcondition-based monitoring of such bearings in servomotor applications, where typicallythe motor in its normal mode of operation has to follow a non-constant angularvelocity profile that may contain motion inversions. After describing and analyzingthe algorithm from a theoretical point of view, experimental results obtained on areal industrial application are presented and commented
2012
- An Inertial/RFID based localization method for autonomous lawnmowers
[Relazione in Atti di Convegno]
Levratti, A.; Bonaiuti, M.; Secchi, C.; Fantuzzi, C.
abstract
Robotic lawnmowers currently available in the market cover their assigned area using a random reflection navigation strategy. While this strategy has been widely accepted for autonomous vacuum cleaning systems, it poses quality problems in outdoor applications since a randomic crossing of the garden can lead to an uneven mowing. In this paper we propose a localization algorithm based on a modified Constrained Kalman Filter that allows to implement an efficient navigation strategy and to increase the quality of service of the mower. This method properly merges data coming from an Inertial Measurement Unit (IMU) and from an RFID (Radio-Frequency IDentification) antenna with information given by the Hall sensors of the wheels of the robot. The proposed algorithm has been verified first by simulation, and then with experiments by building a prototype lawnmower robot. © 2012 IFAC.
2012
- Decentralized Global Connectivity Maintenance for Interconnected Lagrangian Systems with Communication Delays
[Relazione in Atti di Convegno]
Secchi, Cristian; Sabattini, Lorenzo; Fantuzzi, Cesare
abstract
n order to accomplish cooperative tasks, multi robot systems are required to communicate among each other. Thus, maintaining the connectivity of the communication graph is a fundamental issue. In this paper we extend the connectivity maintenance control strategy introduced in (Sabattini et al., 2012), in order to explicitly take into account the presence of communication delays. When dealing with interconnected robotic systems, in fact, assuming instantaneous exchange of data is often unrealistic. For this reason, we provide a solution to the connectivity maintenance problem for interconnected Lagrangian dynamical agents, in the presence of communication delays.
2012
- Diagnostic approach for an automated filling machine: setupand preliminary results
[Relazione in Atti di Convegno]
M., Cotogno; G., Prata; Cocconcelli, Marco; Fantuzzi, Cesare; Rubini, Riccardo
abstract
High production rate machinery is more sensitive to stops and maintenance strategy due to higher loss of production. This paper presents the initial steps of a methodology which aim to realize a condition monitoring system to be embedded on a medicine capsule filler machine. The first required is the gathering and classifying of the machine criticalities, and in this paper a FMEA (Failure Mode and Effects Analysis) is performed, resulting in a cam follower as the main machine fault cause. Subsequently the initial phases of the diagnostic parameter identification process are presented. In this case the parameters chosen are the machine vibration data coming from a triaxial sensor mounted in 4 different locations on the machine. The selection of the best combination of accelerometer-location/accelerometer-axis involves the evaluation of the averaged vibration data and some of their statistical indicator such peak level, RMS and kurtosis. This approach has been applied in a framework of a applied research supported by Emilia Romagna Region, with the cooperation of LIAM (Industrial Laboratory for Packaging Machine Automation) and the company I.M.A. (Industria Macchine Automatiche)
2012
- Experimental comparison of 3D vision sensors for mobile robot localization for industrial application: stereo–camera and RGB–D sensor
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Levratti, Alessio; F., Venturi; E., Amplo; Fantuzzi, Cesare; Secchi, Cristian
abstract
While RGB–D sensors are becoming more and more popular in mobile robotics laboratories, they are usually not yet adopted for industrial applications. In fact, in this field, depth measurements are generally acquired by means of laser scanners and, when visual information is needed, by means of stereo– cameras. The aim of this paper is to perform an experimental validation, to compare the performance of a stereo–camera and an RGB–D sensor, in a specific application: mobile robot localization for industrial applications. Experiments are performed exploiting artificial landmarks (defined by a self–similar pattern), placed in known positions in the environment.
2012
- Hardware in the loop simulation for distributed automation systems
[Relazione in Atti di Convegno]
Fantuzzi, C.; Panciroli, R.; Gargiulo, M.
abstract
The verification and validation (V&V) of the controllers for complex mechatronic devices is an important step to assure performance and quality of the overall system. In particular, in the field of manufacturing of automatic packaging machines, it is common practice postpone the development of the control system until the mechanical part of the machine is finalized. This fact have rose the issue about simulation techniques to support the controller V&V at early development stage of the machine, to parallelize the development of the control and the mechanics. In particular, the Hardware in the Loop (i.e. the connection of the real controller with a simulated model of the machine) is currently under consideration by several researchers for provide support to the V&V of the system. This paper presents a methodology for the development of a HIL simulation which aims to the V&V of the distributed control system at early development stage of a packaging machine. © 2012 IEEE.
2012
- Model-driven approach to design ICT infrastructure for precision farming
[Relazione in Atti di Convegno]
Kaitovic, I.; Rezende, R.; Murillo, C.; Fantuzzi, Cesare
abstract
Design of complex systems involving a number of experts
from different fields always includes modeling at
many levels of abstraction. Still, each modeling
methodology, including model--driven approach using
UML, requires partners coming from an area
different software engineering to learn a new
language and adapt themselves to the new
methodology. As this can be tedious and even contra
effective with respect to efficient project
manage-ment, we propose an adaption and a
simplification of this, traditional, approach. We
believe that the approach is easy to be understood
and applied but still results in an useful model
that can serve as a mutual understanding
platform. We present the application of the
methodology as we achieve a full and detailed
structural model of in-frastructure for precision
farming. Modeled infrastruc-ture is an open ICT
hardware-software solution based on ISOBUS
specification that enables partial automation of
tractors increasing safety and production
efficiency
2011
- A building block for the decomposition analysis of production lines with restart policy
[Relazione in Atti di Convegno]
Gebennini, Elisa; Grassi, Andrea; Fantuzzi, Cesare
abstract
The paper presents a method for the performance evaluation of long lines with machines controlled by a restart policy. The restart policy, typical of packaging lines in the food and beverage industry, aims to reduce the occurrence of blocking events on critical machines: when any critical machine gets blocked sinceits downstream buffer is full, it is prevented from resuming production until the buffer is once again empty.First, an analytical model for a building block with restart policy and multiple failure modes is developed and its solution derived. Then, the paper shows how the new model can be included in a decomposition technique based on a multiple failure approach. Some validation results are also provided for three-machine two-buffer lines with a restart policy on the first machine.
2011
- A Design Pattern for translating UML software models into IEC 61131-3 Programming Languages
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; M., Bonfè; F., Fanfoni; Secchi, Cristian
abstract
The paper deal with a deep analysis and application of object-oriented methodologies for the design process of industrial machine controllers. The process pass thought the phases of (1) conceptual model development of the software artifacts, and (2) model code deployment for the automation system target, which is in general a Programmable Logic Controller (PLC) compliant with the international standard IEC 61131-3 for programming languages. The paper describes a design pattern for the software conceptual model deployment, with a particular emphasis on practical requirements enforced by PLC of different brands. In fact, IEC 61131-3 compliance provides a common ``look-and-feel'' for programming languages, but does not guarantee straightforward code portability between different PLC vendors. The paper has a great focus on applications and provides an example, based on a generic flow-pack machine, to better explain the proposed methodology.
2011
- A Graph-Based Collision- Free Distributed Formation Control Strategy
[Relazione in Atti di Convegno]
R., Falconi; Sabattini, Lorenzo; Secchi, Cristian; C., Melchiorri; Fantuzzi, Cesare
abstract
n this paper we describe a consensus based control strategy to obtain a formation of groups of mobile robots. Weighted graphs are used to obtain the desired formation-shape while avoiding collisions among the robots. Since mobile robots usually move in unknown and unstructured environments, we show how to extend our control strategy to make the robots avoid collision with obstacles as well. To validate our control strategy, we provide both analytical proofs and simulative and experimental results.
2011
- A SysML based methodology for manufacturing system modeling and design
[Articolo su rivista]
L., Bassi; Secchi, Cristian; Fantuzzi, Cesare; M., Bonfé
abstract
This paper describes a modeling methodology to support the design process of complex systems. The main challenge in modern industrial applications is the sheer volume of data involved in the design process. While using high-level abstraction is necessary to manage this data and analyze the system “as a whole,” designers need also to retain all the low-level information of the system, in order to be able to perform optimizations and modifications at later times. The solution proposed here is to use a hierarchy of models, each one describing the system at different levels of abstraction, and arrange them in such a way that it is possible to easily “map” each level onto the others. The topmost layer of the system description is expressed in System Modeling Language, a general-purpose modeling language based on Unified Modeling Language.
2011
- AGV Global Localization Using Indistinguishable Artificial Landmarks
[Relazione in Atti di Convegno]
D., Ronzoni; R., Olmi; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we consider the global localization problem for an industrial AGV moving in a known environment. The problem consists of determining the pose of the vehicle without any prior information about its location. The vehicle is supposed to be equipped with a laser scanner that allows to measure the range and bearing of the vehicle with respect to a set of anonymous landmarks. A map with the positions of all landmarks in the environment is available to the localization system. We propose a novel algorithm for AGV self-localization based on landmarks identification that can take into account also false detections, very common in industrial environments. The pose is computed with a single scan (2D), without any sensor fusion. The performance of the proposed strategy is shown both by simulations and experiments on real industrial plants.
2011
- An Efficient Control Strategy for the Traffic Coordination of AGVs
[Relazione in Atti di Convegno]
R., Olmi; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we propose an algorithm for coordinating a fleet of Automated Guided Vehicles (AGVs) that go through predefined paths in a dynamic industrial environment. Coordination diagrams are used to define a mapping between the configuration space of the fleet and a set of motion constraints that the vehicles must satisfy in order to avoid mutual collisions. The motion actions that maximize the advancement of the fleet while respecting the constraints are determined by a polynomial time heuristic algorithm.
2011
- Arbitrary shaped formations of mobile robots: Artificial Potential fields and coordinate transformation
[Articolo su rivista]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we describe a novel decentralized control strategy to realize formations of mobile robots. We first describe how to design artificial potential fields to ob- tain a formation with the shape of a regular polygon. We provide a formal proof of the asymptotic stability of the sys- tem, based on the definition of a proper Lyapunov function. We also prove that our control strategy is not affected by the problem of local minima. Then, we exploit a bijective coordinate transformation to deform the polygonal forma- tion, thus obtaining a completely arbitrarily shaped forma- tion. Simulations and experimental tests are provided to val- idate the control strategy.
2011
- Coordination of Industrial AGVs
[Articolo su rivista]
R., Olmi; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper, we propose an algorithm for coordinating a group of mobile robots that go through predefined paths in a dynamic industrial environment. Coordination diagrams are used for representing the possible collisions among the vehicles. We exploit this information for developing a centralised and incremental planning algorithm that allows to coordinate the vehicles and to take into account unexpected events that can occur in an industrial environment. Simulation tests have been executed in order to compare the performance of our algorithm with the one currently implemented by the company.
2011
- Time-Complemented Event-Driven Control Framework for Distributed Motion Control Systems Based on IEC 61499 and IEEE 1588
[Relazione in Atti di Convegno]
C., Pang; V., Vyatkin; Fantuzzi, Cesare
abstract
This paper presents a preliminary study towards the applications of IEC 61499 Function Block standard in distributed motion control systems, where synchronization is of crucial importance. In particular, an investigation on the possibilities of applying event-driven function blocks in the time-based motion control system has been performed on the SIDEL SL90 packaging machine's control system. To achieve the required high-precision time synchronization and to provide the reference time, the IEEE 1588 Precision Time Protocol has been implemented in this work as the essential part of the packaging control system. A time-complemented event-based control framework has also been proposed.
2010
- A methodology for the design of simulation campaigns based on population variance characterization
[Relazione in Atti di Convegno]
Grassi, Andrea; Gebennini, Elisa; Perrica, Giuseppe; Fantuzzi, Cesare; Rimini, Bianca
abstract
Manufacturing industrial systems are complex systems whose performance is characterized by interactions among different parts of the system as well as by stochastic phenomena affecting the operation of the parts themselves.A key aspect in studying a complex system is the ability to model its evolution over time and, as a consequence, to identify, from a statistical point of view, the trend of the performance measures (i.e. productivity) over time. Discrete event system simulation (DESS) is certainly the widespread technique adopted to this aim.In this paper, a methodology to characterize the trend of the variance of the population for a flow-line production system is developed. The knowledge of the relation between the variance of the population and the system run time allows the analyst to better design simulation campaigns and define warm-up period. Moreover, this result is also useful when in-field tests have to be designed to certify performances of a newly deployed system.
2010
- A nonlinear proportional controller for motion control application
[Relazione in Atti di Convegno]
Fantuzzi, C.; Canini, G.
abstract
This paper concerned the theoretical design and the experimental test of a simple nonlinear proportional controller. The controller is based on a gain scheduling approach, in which a model-based procedure is used to define the switching policy. The design procedure has been applied to a position control loop based on an AC electrical motor. Results from the experimental tests show that nonlinear controller performs better in terms of reference trajectory tracking compared with standard proportional control. © 2010 IEEE.
2010
- An Algorithm to Diagnose Ball Bearings Faults in Servomotors Running Arbitrary Motion Profiles
[Relazione in Atti di Convegno]
L., Bassi; Cocconcelli, Marco; Secchi, Cristian; Rubini, Riccardo; Fantuzzi, Cesare
abstract
-
2010
- An engineering process for the mechatronic development of industrial automation systems
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; F., Fanfoni; Secchi, Cristian; M., Bonfé
abstract
This paper deals with the development process of an industrial application for the manufacturing of artefacts and products. In particular, a new engineering process tackling the whole machine life-cycle, from the user requirements capture, the project conceptual development to the final machine delivery and acceptance tests, is presented. The process is particularly tailored to the development of automated machines for the beverage and liquid food packaging market, and it is illustrated with a real case study developed in cooperation with a market leader machine manufacturer.
2010
- Automatic experiments design for discrete event system simulation
[Relazione in Atti di Convegno]
Perrica, Giuseppe; Fantuzzi, Cesare; Grassi, Andrea; G., Goldoni
abstract
In discrete event system simulation, random samples from probability distributions are typically used as input for a model.Since these samples are just a sequence of observations generated by random processes that could have large variability, therefore the results of each run can vary substantially. As a consequence, a suitable number of replications must be executed in order to provide good accuracy on estimation of key performance indicators. This paper aims to propose two systematic approaches to manage simulation campaigns automatically. The method behind these approaches increase the runs' number iteratively in order to reduce error on performance indicator estimation, thus respecting precision requirements on simulation output results. The presented approaches can be used for both terminating and non-terminating systems.
2010
- Bird's - Eye View Image for the Localization of a Mobile Robot by Means of Trilateration
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare; A., Stefani
abstract
In this paper we introduce a method for the localization of a low–cost mobile robot,based on the use of a monocular camera. We consider a robot moving in a bi–dimensionalenvironment, where some landmarks are placed in known positions. The acquired image of theenvironment is converted into a bird’s–eye view image, used to measure the distance of the robotfrom the landmarks, to compute the robot’s position by means of trilateration. The proposedstrategy is able to compute both the position and the orientation of the robot.
2010
- Coordinating multiple robots with assigned paths
[Relazione in Atti di Convegno]
R., Olmi; Secchi, Cristian; Fantuzzi, Cesare
abstract
This paper describes a method for coordinating the motions of a group of robotsfollowing predefined paths in a common workspace. Coordination Diagrams (CD) are used forrepresenting the possible collisions among the robots. We propose an algorithm that computesa complete coordination plan for the overall missions that each vehicle have to execute. Thealgorithm generates a set of possible coordination plans and then gives the optimal one. Previousworks apply traditional path planning techniques (such as D* or A*) to compute a coordinatedmotion. However these techniques do not take into account the fact that the CD has a cylindricalstructure. This important features enables our algorithm to explore the CD in a more efficientlyway.
2010
- Coordinating the motion of multiple AGVs in automatic warehouses
[Relazione in Atti di Convegno]
R., Olmi; Secchi, Cristian; Fantuzzi, Cesare
abstract
2010
- Coordination of multiple robots with assigned paths
[Relazione in Atti di Convegno]
Olmi, R.; Secchi, C.; Fantuzzi, C.
abstract
This paper describes a method for coordinating the motions of a group of robots following predefined paths in a common workspace. Coordination Diagrams (CD) are used for representing the possible collisions among the robots. We propose an algorithm that computes a complete coordination plan for the overall missions that each vehicle has to execute. The algorithm generates a set of possible coordination plans and then gives the optimal one. Previous works apply traditional path planning techniques (such as D* or A*) to compute a coordinated motion. However these techniques do not take into account the fact that the CD has a cylindrical structure. This features enables our algorithm to explore the CD in a more efficient way.
2010
- Tracking of Closed-Curve Trajectories for Multi-Robot Systems
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare; D., de Macedo Possamai
abstract
In this paper we address the trajectory tracking problem for groups of mobile robots. We consider trajecto- ries described by completely arbitrary shaped closed curves. The proposed control strategy is a completely decentralized algorithm, and does not require any global synchronization. The desired behavior is obtained by means of some properly designed artificial potential functions.
2009
- A Coordination Technique for Automatic Guided Vehicles in an Industrial Environment
[Relazione in Atti di Convegno]
Olmi, Roberto; Secchi, Cristian; Fantuzzi, Cesare
abstract
{One of the most challenging steps of a simulation study is the experiments analysis since it provides the information necessary to make decision regarding project objectives. As a matter of fact, a very common practice is to carry out an arbitrary number of simulation runs of arbitrary length and then to perform inference on the simulation results, treating them as the ``true'' model output. The aim of this paper is to propose an innovative methodology to investigate simulation outputs in order to identify ``sustainable target'' for the system and express it as a point value rather than as a confidence interval. For this purpose, a decision support tool is then proposed, it takes as input the process output data of observed samples and provides as result the achievable targets for each couple of replication number and replication length by using the classical statistical concepts of type-I and type-II error
2009
- A design pattern for model based software development for automatic machinery
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; M., Bonfé; Secchi, Cristian
abstract
The paper presents the results of the application of object-oriented modeling techniques to thecontrol software design of complex manufacturing systems, with particular focus on automaticmachineries for production and packaging of food stu, as milk, snacks, etc.In this application elds there are some peculiar problems to tackle in order to develop eectivesoftware control solutions, as for example the exception handling caused by product or packagingmaterial jam, the Human Machine Interface, the recipe production management etc.The goal of this paper is to introduce design patterns developed in the framework of UML appliedto the development of automatic machineries software, aiming to dene a set of predenedmodeling solutions to some class of recurrent design problems.
2009
- Adoption of control policies in a simulative model for the design of AGV systems
[Relazione in Atti di Convegno]
Gebennini, Elisa; Dallari, Sara; Perrica, Giuseppe; Grassi, Andrea; Rimini, Bianca; Fantuzzi, Cesare
abstract
Nowadays, industrial applications are showing an increasing interest toward the adoption of automated logistic handling systems, such as systems including Automated Guided Vehicles (AGVs). A logistic handling system represents the physical link between the production system (i.e. parallel production lines) and the shipment system (i.e. fleets of vehicles for goods delivery). The synchronization between these two processes is an important issue, especially for companies producing final goods and giving priority to direct shipments rather than to store products inside the plant. Nevertheless, the variability in the generation of production patterns and shipment arrivals may lead to an unacceptable loss of synchronization. In order to prevent this harmful situation, some control policies can be adopted: it could be necessary to review short-term plans acting on production patterns and/or on shipment priority.This paper deals with the design and management of a logistic handling system including AGVs by using a simulation model. Normally, the objective of the design phase is the identification of the optimal number of AGVs to include in the system. For this purpose, an effective simulative model has to consider what happens both in the upstream (i.e. production system) and in the downstream (i.e. shipment system) of the logistic system. Nevertheless, the modeling of a real complex system has also to include the control policies that assure the necessary synchronization between the production and shipment processes. A methodological approach is then proposed and an application to a design problem derived form an actual case study is presented and discussed.
2009
- Comparison Between Time-Frequency Techniques to Predict Ball Bearing Fault in Drives Executing Arbitrary Motion Profiles
[Relazione in Atti di Convegno]
Cocconcelli, Marco; Secchi, Cristian; Rubini, Riccardo; Fantuzzi, Cesare; Bassi, L.
abstract
In this paper Wavelet Transform (WT) and Hilbert-Huang Transform (HHT) are used as bearing diagnostics tools in drives executing arbitrary motion profiles. This field is increasingly drawing the attention of the industries because the modern electric motors work as electric cams inducing the shaft to move with a cyclic variable-velocity profile. The literature papers take into account only a constant velocity profile and they are not suitable for such applications. In fact literature methods analyse the signal only in the frequency domain, while in variable-velocity condition the bearing diagnostics should be performed in time domain. Both WT and HHT are time-frequency techniques which describe an input signal as a sum of specific functions. These functions are compared with a signal which simulates the expected vibrations of a bearing with a given fault, e.g. on the outer race. The comparison is done through a cross-correlation between the expected signal and the time-frequency techniques output. WT and HHT are used separately in an industrial case, which consists in bearing fault prediction in an automated packaging machine. In the end of the paper the WT and HHT results are discussed to analyse the different responses.
2009
- Formation Control over Delayed Communication Networks
[Relazione in Atti di Convegno]
Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we address the problem of formation control of a group ofrobots that exchange information over a communication network characterized by anon negligible delay.We consider the Virtual Body Artificial Potential approach forstabilizing a group of robots at a desired formation. We show that it is possible tomodel the controlled group of robots as a port-Hamiltonian system and we exploitthe scattering framework to achieve a passive behavior of the controlled system andto stabilize the robots in the desired formation independently of any communicationdelay.
2009
- Mechatronics
[Direzione o Responsabilità Riviste]
Fantuzzi, Cesare
abstract
2009
- On the introduction of a restart policy in the two-machine, one-buffer transfer line model
[Relazione in Atti di Convegno]
Gebennini, Elisa; Grassi, Andrea; Fantuzzi, Cesare; Gershwin, S. B.; Schick, I. C.
abstract
The paper develops an analytical model of transfer lines consisting of two machines decoupled by one finite buffer, in which a restart policy is also added to reduce the occurrence of blocking events in the first machine. Briefly, the first machine is forced to remain blocked each time the buffer fills up until it is once again empty. The system is modeled as a discrete-time discrete-state markov process, and expressions of the most important performance measures are provided.
2009
- Potential Based Control Strategy for Arbitrary Shape Formations of Mobile Robots
[Relazione in Atti di Convegno]
Sabattini, Lorenzo; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we describe a novel decentralized control strategy to realize formations of mobile robots. We first describe a methodology to obtain a formation with the shape of a regular polygon. Then, applying a bijective coordinates transformation, we show how to obtain a formation with an arbitrary shape. Our control strategy is based on the interaction of some artificial potential fields, but it is not affected by the problem of local minima.
2009
- Simulation and analysis of a production line with multiple output formats
[Relazione in Atti di Convegno]
Grassi, Andrea; Perrica, Giuseppe; Gebennini, Elisa; Dallari, Sara; Fantuzzi, Cesare; Rimini, Bianca
abstract
This paper deals with simulation based performance analysis of production lines characterized by the capability to produce multiple product formats at the same time. This situation is typical of several line production systems, mainly in packaging lines where the output consists in different formats of secondary packages containing a different amount of single products. The line is then configured in a first part that works single units of product, and in a second part in which the production flow is split into different branches where specific machines arrange single products in the format needed by the requested secondary package. In the paper, which is derived from an actual case study, key factors of such kind of lines are analyzed and their effects on line performance are investigated. Some crucial aspects and guidelines are then pointed out to constitute a support in the line design phase.
2009
- Target detection for simulated systems
[Relazione in Atti di Convegno]
Perrica, Giuseppe; Goldoni, Gabriele; Grassi, Andrea; Fantuzzi, Cesare
abstract
One of the most challenging steps of a simulation study is the output data analysis, since it provides the information necessary to make decision regarding project objectives. As a matter of fact, a very common practice is to carry out an arbitrary number of simulation runs of arbitrary length and then to perform inference on the simulation results, treating them as the “true” model output.The aim of this paper is to propose an innovative methodology to investigate simulation outputs in order to identify “sustainable target” for the system and express it as a point value rather than as a confidence interval. For this purpose, a decision support tool is then proposed, it takes as input the process output data of observed samples and provides as result the achievable targets for each couple of replication number and replication length by using the classical statistical concepts of type-I and type-II error.
2008
- A SIMULATION BASED APPROACH FOR SUPPORTING AUTOMATED GUIDED VEHICLES (AGVs) SYSTEMS DESIGN
[Relazione in Atti di Convegno]
Gebennini, Elisa; Dallari, S.; Grassi, Andrea; Perrica, G.; Fantuzzi, Cesare; Gamberini, Rita
abstract
Automated Guided Vehicle (AGV) logistic handling systems are widely adopted when high transportation capacity and quality of service are the most important characteristics to reach. A large number of mathematical approaches have been developed in yearsto address AGV systems design and control. Nevertheless, proper performance estimations have to consider the peculiar aspects of the real environment in which the AGV system operates. A simple and effective approach to the stochastic features modelling is the discrete event simulation of the real system. This paper presents a conceptual approach that lead the analyst to set up consistent simulative models to address AGV systems design and performance estimation when applications in end-of-line logistics areconsidered.
2008
- An analytical model for automated packaging lines design
[Relazione in Atti di Convegno]
Gebennini, Elisa; Grassi, Andrea; Secchi, Cristian; Fantuzzi, Cesare
abstract
The problem of deriving a probabilistic mathematical model of an industrial production line is addressed in this paper. In particular, the analysis of a Tetra Pak liquid foodstuff packaging line has been developed as application of the modeling theory. Tetra Pak's package forming machine works on the basis of a continuous process which cannot be interrupted without production wasting. Production buffer are used to decouple package forming machine with following (downstream) machines (e.g. straw applicator, film wrapper, etc.) to avoid forming machine forced stoppage because downstream machine stoppage. The paper presents a new analytical approach for the packaging forming machine restart control policy based on buffer level.
2008
- Authors’ reply to “Comments on ‘Object-Oriented Modeling of Complex Mechatronic Components for the Manufacturing Industry’
[Articolo su rivista]
Secchi, Cristian; M., Bonfé; Fantuzzi, Cesare; R., Borsari; D., Borghi
abstract
In his comments to our paper published on the IEEE Transactions on Mechatronics (Vol. 12, no. 6, pp. 696-702), Kleanthis Thramboulidis points out many issues related to the application of the Object-Oriented modeling approach proposed in the paper. The comments of Thramboulidis are relevant and properly referenced, especially considering the section about UML, its variants (i.e. UML 1.4, UML-RT, UML 2.0) and the conceptual elements of component based design. However, we believe that the author of the comments has focused his attention too much on the software implementation aspects, including engineering tools and run-time execution frameworks for the control software, which are actually outside the scope of the original paper. In this reply, we aim to emphasize the main contribution of the paper and analyse the issues raised in the comments, with particular regard on our plan to address them in future works.
2008
- Chaos: Base mechanisms in circuits
[Relazione in Atti di Convegno]
Perrica, Giuseppe; Fantuzzi, Cesare
abstract
In this paper base-mechanisms of chaos generation in circuits are investigated, underlining that it is a common phenomenon and not a mathematic abstraction. Several examples of chaotic behaviours are presented and their undesired effect or deliberate results are discussed.
2008
- Compensation of position errors in passivity based teleoperation over packet switched communication
[Relazione in Atti di Convegno]
Secchi, C.; Stramigioli, S.; Fantuzzi, C.
abstract
Because of the use of scattering based communication channels, passivity based telemanipulation systems can be subject to a steady state position error between master and slave robots. In this paper, we consider the case in which the passive master and slave sides communicate through a packet switched communication channel (e.g. Internet) and we provide a modification of the slave impedance controller for compensating the steady state position error arising in free motion because of packets loss. Copyright © 2007 International Federation of Automatic Control All Rights Reserved.
2008
- Compensation of position errors in passivity based teleoperation over packet switched communication networks
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S; Fantuzzi, Cesare
abstract
Invited paper nella sessione intitolata “Putting Energy back in Robotics”.
2008
- Coordination of Multiple AGVs in an Industrial Application
[Relazione in Atti di Convegno]
Olmi, R; Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we propose a methodology for coordinating a group of mobile robots following predefined paths in a dynamic industrial environment. Coordination diagrams are used for representing the possible collisions among the robots. Exploiting the structure of the industrial application we are dealing with, we propose an algorithm for efficiently composing the coordination diagram. Furthermore, we classify the possible collisions that can take place and the induced geometry of the resulting coordination diagram. Finally, we exploit this information for developing a planning algorithm that allows to coordinate the robots and to take into account unexpected events that can occur in an industrial environment.
2008
- Formation Control Over Delayed Communication Networks
[Relazione in Atti di Convegno]
Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we address the problem of formation control of a group of robots that exchange information over a delayed communication network. We consider the Virtual Body Artificial Potential approach for stabilizing a group of robots at a desired formation. We show that it is possible to model the controlled system as a set of elements exchanging energy along a power preserving interconnection structure. We exploit the scattering framework to stabilize the robots in the desired formation independently of any delay in the communication of the information.
2008
- Predictive maintenance of ball bearings for machines rotating with arbitrary velocity profiles
[Relazione in Atti di Convegno]
Cocconcelli, Marco; Secchi, Cristian; Rubini, Riccardo; Fantuzzi, Cesare; Bassi, L.
abstract
Recent research and development on direct–drive motor technology and on their control system push forwardthe application of these devices as electric cams in a large numbers of industrial applications, such as examplemotion control system for packaging machineries. Performances of these devices are much higher than themechanical solutions for machine motion, in terms of precision and operational speed, and, of course, intime required to reconfigure the motion profile.However, classical approaches to the ball bearing diagnosis that use analysis of vibration signals are notlonger applicable, as they have been developed on the hypothesis of drive constant speed. In fact, in mostof the current industrial application, the control system drives the motor to follow a complex and cyclic (i.e.motor shaft reverses its motion direction at each operational cycle) non constant speed motion profile.In those application, even Computed Order Tracking [1] (COT), which is the main fault bearing diagnosistechnique used in non-constant velocity applications, fails to detect incipient faults, as highlighted by Fyfeand Munck in [2].This paper presents a new procedure that modifies the COT to be successfully applicable to the diagnosisproblem of ball bearings in variable speed motion applications.
2008
- Time to Failure and Time to Repair Profiles Identification
[Relazione in Atti di Convegno]
Perrica, Giuseppe; Fantuzzi, Cesare; Grassi, Andrea; G., Goldoni; F., Raimondi
abstract
This paper covers with the identification of real statistical distribution of time to failure (TTF) and time to repair (TTR) of a manufacturing production line. A formal procedure to obtain TTF and TTR profile distributions (location, scale and shape parameters) has been defined. The procedure processes redundant and corrupted signals logged from control systems of the manufacturing machines during operative phases (i.e. alarms and process data). We define a formal algorithm to filter the data and establish the qualitative and quantitative characteristics for reliability applications. This procedure has been applied to data acquired from a Tetra Pak packaging line. The resulting TTF and TTR profiles have been used to define statistical failure and restoration input in simulation campaigns of a packaging line.
2008
- Transparency in Port-Hamiltonian-Based Telemanipulation
[Articolo su rivista]
Secchi, Cristian; S., Stramigioli; Fantuzzi, Cesare
abstract
After stability, transparency is themajor issue in the design of a telemanipulation system. In this paper, we exploit the behavioral approach in order to provide an index for the evaluation of transparency in port-Hamiltonian-based teleoperators. Furthermore, we provide a transparency analysis of packet switching scattering-based communication channels.
2008
- Variable Delay in Scaled Port-Hamiltonian Telemanipulation
[Articolo su rivista]
Secchi, Cristian; S., Stramigioli; Fantuzzi, Cesare
abstract
In several applications involving bilateral telemanipulation, master and slave robots act at different power scales (e.g. telesurgery, micromanipulation). Scaling forces and velocities means scaling the power that is exchanged between master and slave sides through the communication channel. In this paper weshow how it is possible to embed power scaling in the scattering based communication channel used in port-Hamiltonian based telemanipulation. Furthermore, a strategy for passively dealing with variable communication delay is proposed in order to allow scaled teleoperation over packet switched networksas Internet.
2008
- Verification of Fault Tolerance of Discrete-Event Object-Oriented Models using Model Checking
[Relazione in Atti di Convegno]
Bonfe', M; Fantuzzi, Cesare; Secchi, Cristian
abstract
The Object-Oriented (O-O) approach has been recently used in the industrialautomation to design logic control systems, thanks to the features of specification languages(e.g. UML) that can help to describe event-based behavioral requirements. In this paper, weaim to formalise an O-O framework for the design of modular logic controllers, in which faultsoccurring in the plant can alter the behavior of closed-loop system. Given the formal model ofthe system in terms of Kripke structures, it is possible to verify with model checking that evenin case of faults the system do not violate given safety and liveness properties. Moreover, we willconsider the case in which an O-O logic controller is refined applying the so-called “design-by-extension” mechanism, in which case it is important to verify that the fault tolerance propertyis inherited by the refined system.
2007
- A port-Hamiltonian approach to the control of interaction
[Capitolo/Saggio]
Secchi, C.; Fantuzzi, C.; Stramigioli, S.
abstract
In many applications, a robot has to interact with the surrounding environment in order to perform some useful task. When a manipulator interacts with an object a very profound change occurs. In fact, before the contact, the controller has to control only the motion of the robot; after the contact, the manipulator dynamically interacts with the environment and the controller has to manage a new dynamical system made up by the robot coupled with the environment. It has been proven in [328] that even if the controlled robot is stable in case of free motion, its behavior could become unstable when there is a contact with the environment. © 2007 Springer-Verlag Berlin Heidelberg.
2007
- A study of fault diagnosis and recovery techniques for manufacturing systems
[Capitolo/Saggio]
Bonfe, M.; Fantuzzi, C.; Simani, S.
abstract
This chapter describes a framework for the development of a diagnosis methodology for industrial manufacturing systems. The aim of the project is to support technicians that supervise the manufacturing plant to identify the causes of faults and failures on the machine and, in particular, to indicate a procedure for the recovery of its working condition. The chapter presents a study as the first step of a design project whose objective is to realize a supervisory system with advanced features devoted to Faults Detection and Isolation (FDI) for the manufacturing industry, with an emphasis on its integration with Human-Machine Interfaces. The requirements described in the chapter are defined giving particular care to the peculiarities of the application domain to allow the design of a powerful, but easy to use for industrial technicians, diagnostic system. An example of a manufacturing machine quite common in the packaging industry is schematized in the chapter, which is analyzed to define the fault trees for the most critical failure modes. © 2007 Copyright © 2007 Elsevier Ltd All rights reserved.
2007
- COMPLEX PACKAGING LINE MODELLING AND SIMULATION
[Relazione in Atti di Convegno]
Grassi, Andrea; Gebennini, Elisa; Goldoni, G.; Fantuzzi, Cesare; Gamberini, Rita; Nevin, R.; Rimini, Bianca
abstract
The paper presents advanced issues in modelling and simulation of complex packaging line. In particular, we developed a theoretical model of a line with two machines and a buffer, which is a simplified version of a real packaging line from Tetra Pak company. The paper reports also about simulation results that confirm theoretical supposals.
2007
- Control of Interactive Robotic Interfaces: a port-Hamiltonian approach
[Monografia/Trattato scientifico]
Secchi, Cristian; S., Stramigioli; Fantuzzi, Cesare
abstract
This monograph deals with energy based control of interactive robotic interfaces and the port-Hamiltonian framework is exploited both for modeling and controlling interactive robotic interfaces. Using the port-Hamiltonian framework, it is possible to identify the energetic properties that have to be controlled in order to achieve a desired interactive behavior and it is possible to build a port-Hamiltonian controller that properly regulates the robotic interface by shaping its energetic properties.Thanks to its generality, the port-Hamiltonian formalism allows to model and control also complex interactive robotic interfaces in a very natural way. In this book, a port-Hamiltonian approach for regulating the interaction between a robot and a local environment, a virtual environment (i.e. haptic interfaces) and a remote environment (i.e. bilateral telemanipulation systems) is developed.
2007
- Control of port-Hamiltonian systems
[Capitolo/Saggio]
Secchi, C.; Fantuzzi, C.; Stramigioli, S.
abstract
Energy plays a central role in the control of physical systems since the "shape" of the energy is related to the stability properties of the system. In fact, it is well known from physics, that every configuration characterized by a (local) minimum of the energy exhibits a (locally) stable behavior. Unfortunately the configuration that naturally corresponds to a minimum of the energy is very seldom the desired configuration for the system. © 2007 Springer-Verlag Berlin Heidelberg.
2007
- Energy Shaping over Networks for Mechanical System
[Relazione in Atti di Convegno]
Secchi, Cristian; Fantuzzi, Cesare
abstract
In this paper we address the problem of the control over networks of mechanical systems. We exploit the scattering framework to extend the energy shaping methodology in case the controller and the plant are interconnected through a delayed network. Furthermore, we exploit a result recently proposed for passivity based telemanipulation for guaranteeing the asymptotic stabilization of the desired configuration also in case of loss of information during the communication as it can very likely happen when using Ethernet-like networks (e.g. Internet).
2007
- Kinematic Compensation in Port-Hamiltonian Telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S; Fantuzzi, Cesare
abstract
One of the main drawbacks of passivity based bilateral telemanipulationover delayed communication channels is the presence of a position drift betweenmaster and slave robots during contact tasks; this kinematic mismatch degradesthe interaction feeling perceived by the user. In this paper we consider port-Hamiltonian based telemanipulators and we exploit the interconnection structureof port-Hamiltonian systems to passively compensate the position drift.
2007
- Modelli orientati agli oggetti per sistemi con dinamiche ibride
[Articolo su rivista]
M., Bonfé; Fantuzzi, Cesare; Secchi, Cristian; S., Simani
abstract
Nel presente articolo viene presentata una metodologia per la modellazione el' analisi di processi industriali, il cui scopo e quello di unificare tutti gli aspetti concettuali coinvolti nello sviluppo delle logiche di controllo. In particolare, I'approccio proposto integra i concetti delle tecniche di modellazione orientate agli oggetti, ampiamente note agli sviluppatori software, con i concetti fondamentali dei Bond Graph, un linguaggio di modellazione per sistemi fisici di natura eterogenea basato sulle interazioni energetiche fra componenti basilari.L' articolo mostra inoltre come i modelli ottenuti con il metodo presentato possano essere analizzati con metodiformali per la verifica di sistemi ibridi, cioe sistemi nei quali dinamiche tempo-continue interagiscono condinamiche discrete e regole logiche.
2007
- Object-Oriented Modeling of Complex Mechatronic Components for the Manufacturing Industry
[Articolo su rivista]
Secchi, Cristian; M., Bonfé; Fantuzzi, Cesare; R., Borsari; D., Borghi
abstract
The advantages of object-oriented modeling, as modularity and reusability of components, are very important also for modeling manufacturing systems and not only for software development. Recently, a unified object-oriented approach for modeling both the logical and the physical part of a manufacturing machine has been proposed. In this paper we show the effectiveness of this new modeling framework on an industrial application. The case study consists of the package forming unit of a filling machine for liquid food packaging, developed by Tetra Pak Carton Ambient S.p.a.
2007
- On the use of UML for modeling mechatronic systems
[Articolo su rivista]
Secchi, Cristian; Bonfe, M; Fantuzzi, Cesare
abstract
This paper describes a modeling language that aims to provide a unified framework for representing control systems, namely, physical plants coupled with computer-based control devices. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows describing both control software and physical components using the same basic concepts, particularly those of capsules, ports, and protocols. Furthermore, it is illustrated how the well-known object-oriented specification language unified modeling language can be adopted, provided an adequate formalization of its semantics, to describe structural and behavioral aspects of control systems, related to both logical and physical parts. Note to Practitioners-The development of an automated system within an industrial setting is a complex task, whose successful result depends on the joint efforts of a team of designers with different scientific backgrounds and specialized knowledge. In fact, an automated system is typically composed of a mechanical assembly, which must be precisely designed and manufactured, and a set of sensors and actuators (e.g., electrical drives, pneumatic systems, etc.), which are, on their turn, controlled most of the time by means of digital processors. course, both electrical parts and control algorithms (e.g., proportional integral, and derivative (PID) regulators, logic and supervisory control, reference trajectories for mechanical motions, etc.) should be designed with the same care given to mechanical aspects. Moreover, it is undeniable that none of the various parts composing the automated system design specification can, on their own, allow engineers to understand the actual behavior of the whole system, especially without a common description language that is understandable for all of the designers. The present paper introduces a unified language which aims to support integrated design specifications of automated systems, including the dynamics of heterogeneous physical assemblies, the discrete-event behavior of distributed control software, and the specification of interface ports between the plant and the control system. With the proposed language, it is possible to obtain a complete picture of the automated system suitable for its simulation, documentation, and validation. The modeling language described in the paper supports the principles of object orientation. This choice moves in the direction of enhancing modularity and reusability properties of design specifications, which are aspects of great importance in the design practice. Moreover, the object-oriented approach to automated systems design proposed in the paper aims to introduce the concept of design by extension in the manufacturing industry. This means that the definition of specialization relationships between classes of components implies that those components should be designed in order to be substitutable with each other, especially from a dynamic point of view. This aspect will be the subject of further papers illustrating other practical insights on the use of object-oriented models for automated systems.
2007
- Physical modeling and port-Hamiltonian systems
[Capitolo/Saggio]
Secchi, C.; Fantuzzi, C.; Stramigioli, S.
abstract
Interaction between physical systems is determined by an exchange of energy and, therefore, a first step towards the control of interaction is to explicitly model the energetic properties of physical systems. © 2007 Springer-Verlag Berlin Heidelberg.
2007
- Port-contact systems in bilateral telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S; Fantuzzi, Cesare
abstract
In this paper we develop one of the first control applications of therecently proposed port-contact framework. We show how it is possible to modeland control a bilateral telemanipulation system using port-contact systems andwe develop a port-contact impedance controller that allows to impose a desiredinteractive behavior and a zero steady state position error during contact tasks.
2007
- Port-Hamiltonian based bilateral telemanipulation
[Capitolo/Saggio]
Secchi, C.; Fantuzzi, C.; Stramigioli, S.
abstract
Telemanipulation is one of the first fields of application of robotics (see [326] for an early history) and still one of the most challenging. In teleoperation a human operator has to perform a certain task on a remote environment. The human operator commands a local robotic interface (called master). The motion of the master is transmitted through a communication channel to a remote robot (called slave) which should replicate the motion of the master and perform a desired task on the remote environment. It is possible to improve performances providing to the human operator some real-time information about the interaction of the slave with the remote environment. This feedback information can be achieved in several ways (e.g. through visual displays, [146]) but the best way to improve the operator's ability is to feedback the contact force between the slave and the environment to the master side. When the force at the slave side is reflected back to the human operator, it is said that the telemanipulation is controlled bilaterally, or, more simply, that we have a bilateral telemanipulation system. When teleoperation is performed over a great distance, such as in undersea or in space applications, or over packet switching network, such as the Internet, the communication delay associated to the transmission of information from master side to slave side and vice-versa becomes non negligible and it can therefore destabilize the whole system. © 2007 Springer-Verlag Berlin Heidelberg.
2007
- Power scaling in port-Hamiltonian telemanipulation over packet switched networks
[Capitolo/Saggio]
Secchi, Cristian; S., Stramigioli; Fantuzzi, Cesare
abstract
The aim of this contribution is to provide a communication strategythat allows power scaling over a packet switched communication channel in a digital port-Hamiltonian based telemanipulation scheme. We will firstly prove that in case of negligible communication delay, power scaling can beachieved without compromising the stable behavior of the telemanipulationscheme. Secondly, we will propose a novel scattering based communicationstrategy that allows to scale the power exchanged also in case of non negligiblecommunication delay. Finally we will consider the problem of loss of packetsin the communication; we will show that if lost packets are not properly handledthe system can become unstable and then we will propose a strategy thatpreserves the stable behavior of the overall scheme independently of the lossof packets.
2007
- PWA dynamic identification for nonlinear model fault detection
[Capitolo/Saggio]
Simani, S.; Fantuzzi, C.
abstract
This chapter addresses the identification of nonlinear dynamic systems. A wide class of these systems can be described using nonlinear time-invariant regression models that can be approximated by means of piecewise affine prototypes with an arbitrary degree of accuracy. This chapter concerns the identification of piecewise affine model structure through input-output data acquired from a dynamic process. The identification approach exploited to estimate order and parameters of the local affine models is based on the Frisch scheme method for Error-in-Variables (EIV) models. An optimization technique, taking into account both continuity constraint fulfillment and EIV noise assumptions, is considered. To show theeffectiveness of the developed technique, when exploited also for Fault Detection and Isolation (FDI) purpose, the results obtained in the identification of both a simple simulated system and a real dynamic process are reported. © 2007 Copyright © 2007 Elsevier Ltd All rights reserved.
2007
- Transparency in port-Hamiltonian based telemanipulation
[Capitolo/Saggio]
Secchi, C.; Fantuzzi, C.; Stramigioli, S.
abstract
Stability is a key issue in the implementation of a bilateral telemanipulation system since both the non-negligible time delay in the communication between master and slave and the interaction with unknown environments can destabilize the whole system. In Chap. 4 it has been shown that passivity theory and port-Hamiltonian systems can be fruitfully used to build an intrinsically passive telemanipulation scheme which, therefore, has a stable behavior both in case of free motion and in case of contact with any passive, possibly unknown, environment. Scattering theory has been used to build a communication channel which is lossless independently of any constant transmission delay and the problem of wave reflection arising when coupling master and slave side through scattering based communication channels has been solved. The scheme has been extended in order to take into account the sampled data nature of controllers in a passive way. Moreover discrete scattering has been defined and packet-switching transmission lines have been considered. A communication strategy that allows to preserve passivity even in case of loss of packets and of variable transmission delay has been proposed. Finally, a passivity preserving algorithm that allows to rebuild lost packets by interpolation has been proposed. © 2007 Springer-Verlag Berlin Heidelberg.
2006
- A coalgebraic approach to behavioral inheritance in Dynamical Systems
[Relazione in Atti di Convegno]
Secchi, Cristian; Bonfe', M; Fantuzzi, Cesare
abstract
The paper introduces a formal definitionof inheritance, which is a cardinal concept inobject-oriented software, for dynamical systems. Theproposed definition exploits the coalgebraic descriptionof software artifacts to provide a connection betweenthe behavioral approach for modeling dynamicalsystems and the object-oriented approach for softwaremodeling and design
2006
- A Distributed Embedded Control System for Agricultural Machines
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; Ruggeri, M.; Marzani, S; Secchi, Cristian
abstract
This paper concerns the description of a distributed embedded control system for agricultural machines, as tractors and off-road vehicles. The distributed control system is based on the international standard ISO 11783, also known as ISOBUS standard. The paper describes the safety and system integrity analysis of a hybrid network for off-highway vehicles where ISOBUS and FlexRay protocols co-exist.
2006
- A study of fault diagnosis and recovery techniques for manufacturing systems
[Relazione in Atti di Convegno]
M., Bonfè; Fantuzzi, Cesare; S., Simani
abstract
The paper describes a framework for the development of a diagnosismethodology for industrial manufacturing systems. The aim of the project is tosupport technicians that supervise the manufacturing plant to identify the causesof faults and failures on the machine and, in particular, to indicate a procedurefor the recovery of its working condition. The requirements described in the paperhave been defined giving particular care to the peculiarities of the applicationdomain, in order to allow the design of a powerful, but easy to use, diagnosticsystem for industrial technicians
2006
- An object-oriented approach to manufacturing systems modeling
[Relazione in Atti di Convegno]
Bassi, L; Fantuzzi, Cesare; Bonfe', M; Secchi, Cristian
abstract
This paper describes a methodology to support the design process of complex systems. The main challenge in modern industrial applications is the sheer volume of data involved in the design process. While using high-level abstraction is necessary to manage this data and analyze the system "as a whole", designers need also to retain all the low-level information of the system, in order to be able to perform optimizations and modifications at later times. The solution proposed here is to use a hierarchy of models that describe the system at different levels of abstraction, and are arranged in such a way that is possible to easily "map" each level onto the others. The topmost layer of the system description is expressed in System Modeling Language (SysML), a general-purpose modeling language based on UMLreg
2006
- Behavioural inheritance in object-oriented models for mechatronic systems
[Articolo su rivista]
M., Bonfé; Secchi, Cristian; Fantuzzi, Cesare
abstract
Abstract: This paper describes a formal framework for Object-Oriented (O-O) modelling of mechatronic systems, whose main contribution is, on the one hand, to unify the modelling approaches for dynamical systems and for industrial control software and, on the other hand, to provide a definition of inheritance, a cardinal concept in object-orientation, which emphasises the behavioural conformity of basic and derived classes of objects. The proposed framework exploits the coalgebraic description of software artefacts to provide a connection between the behavioural approach for modelling dynamical systems and the O-O approach for software modelling and design. In particular, our definition of inheritance aims to allow control engineers to apply the design by extension methodology, widely used in software engineering, to the development of mechatronic components for manufacturing systems.
2006
- Design by Extension and Inheritance of behavior in Dynamical Systems
[Relazione in Atti di Convegno]
Secchi, Cristian; Bonfe', M; Fantuzzi, Cesare
abstract
The paper introduces a formal definition of inheritance, which is a cardinal concept in object-oriented software, for dynamical systems. The proposed definition exploits the coalgebraic description of software artifacts to provide a connection between the behavioral approach for modeling dynamical systems and the object-oriented approach for software modeling and design. This definition allows to apply the design by extension methodology, widely used in software engineering, to the design of components of manufacturing systems
2006
- Dynamic system identification and model-based fault diagnosis of an industrial gas turbine prototype
[Articolo su rivista]
Simani, S; Fantuzzi, Cesare
abstract
In this paper, a model-based procedure exploiting analytical redundancy for the detection and isolation of faults on a gas turbine process is presented. The main point of the present work consists of exploiting system identification schemes in connection with observer and filter design procedures for diagnostic purpose. Linear model identification (black-box modelling) and output estimation (dynamic observers and Kalman filters) integrated approaches to fault diagnosis are in particular advantageous in terms of solution complexity and performance. This scheme is especially useful when robust solutions are considered for minimise the effects of modelling errors and noise, while maximising fault sensitivity. A model of the process under investigation is obtained by identification procedures, whilst the residual generation task is achieved by means of output observers and Kalman filters designed in both noise-free and noisy assumptions. The proposed tools have been tested on a single-shaft industrial gas turbine prototype model and they have been evaluated using non-linear simulations, based on the gas turbine data.
2006
- Flexray and isobus integration for off-road vehicles: new standards together for safety and effective applications
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; M., Ferretti; A., Pavesi; Marzani, S.
abstract
This paper makes an analytical overview of a hybrid network for off-highway vehicles where ISOBUS and FlexRay protocols co-exist. A functional analysis has been conducted and a methodology for a quantitative evaluation of the overall system (in terms of performance and reliability) is carried out. The experiments described here (including also the timeframe for future works) take the move from the framework depicted by regional funded project Pro-Tract: a lab has been set up to investigate these and others (Tesauri et al. 2005, [28]) items related to off-highway vehicles.
2006
- Inheritance for Dynamical Systems
[Relazione in Atti di Convegno]
Secchi, Cristian; Fantuzzi, Cesare
abstract
Object-orientation is a very effective approach formodeling complex manufacturing systems. In this paper we introducea formal definition of behavioral inheritance for dynamicalsystems based on the recently proposed coalgebraic descriptionof object-oriented software. This definition allows to extendthe design by extension methodology, widely used in softwareengineering, to the design of components of manufacturingsystems.
2006
- Intrinsically Passive Force Scaling in Haptic Interfaces
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S; Fantuzzi, Cesare
abstract
In several applications involving haptic interfaces it can be desirable to scale the interaction force perceived by the user. The most intuitive approach is to change the stiffness of the virtual environment but, unfortunately, changing the physical parameters that characterize a virtual environment is a potentially destabilizing action. In this paper we embed in the intrinsically passive haptic scheme recently proposed in S. Stramigioli et al. (2005) a power scaling interconnection that allows to scale the force perceived by the user while preserving the passivity, and consequently the stable behavior, of the overall system
2006
- Position drift compensation in port-Hamiltonian based telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S; Fantuzzi, Cesare
abstract
Passivity based bilateral telemanipulation schemes are often subject to a position drift between master and slave if the communication channel is implemented using scattering variables. The magnitude of this position mismatch can be significant during interaction tasks. In this paper we propose a passivity preserving scheme for compensating the position drift arising during contact tasks in port-Hamiltonian based telemanipulation improving the kinematic perception of the remote environment felt by the human operator
2006
- PWA Dynamic Identification for Nonlinear Model Fault Detection
[Relazione in Atti di Convegno]
S., Simani; Fantuzzi, Cesare
abstract
This paper addresses the identification of non–linear dynamic systems. A wide class of these systems can be described using nonlinear time-invariant regression models, that can be approximated by means of piecewise affine prototypes with an arbitrary degree of accuracy. This work concerns the identification of piecewise affine model structure through inputoutput data acquired from a dynamic process. In order to show the effectiveness of the developed technique, when exploited also for FDI purpose, the results obtained in the identification of both a simple simulated system and a real dynamic process are reported.
2006
- Safety and System Integrity of Isobus Applications for Agricultural Machine Control System (AMCS)
[Relazione in Atti di Convegno]
M., Ruggeri; S., Marzani; Fantuzzi, Cesare; R., Montanari
abstract
This paper concerns the safety and system integrity analysis of a typical ISOBUS implementation for the communication network of a distributed mechatronics system for agricultural machines. Despite ISOBUS, described by the international standard communication network, is standardized under the norm ISO11783, we will make an analytical overview of a hybrid network for off-highway vehicles where ISOBUS and FlexRay protocols co-exist. A functional analysis has been conducted and a methodology for a quantitative evaluation of the overall system (in terms of performance and reliability) is carried out. The experiments described here (including the timeframe for future works) take the move from the framework depicted by the regional-funded project Pro-Tract: a lab has been set up to investigate these items related to off-highway vehicles.
2006
- Towards Object-Oriented Modeling of Complex Mechatronic Systems for the Manufacturing Industry
[Relazione in Atti di Convegno]
Zanichelli, D; Secchi, Cristian; Rubini, Riccardo; Fantuzzi, Cesare; Bonfe', M; Borghi, D; Borsari, R; Sacchetti, E.
abstract
The advantages of object-oriented modeling, as modularity and reusability of components, are very important also for modeling manufacturing systems and not only for software development. In [1] a unified object-oriented approach for modeling both the logical and the physical part of a manufacturing machine has been proposed. In this paper we report an industrial application of this modeling strategy and the case study consists of the package forming unit of a filling machine for liquid food packaging, developed by Tetra Pak Carton Ambient S.p.a.
2006
- Variable delay in scaled port-Hamiltonian telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S; Fantuzzi, Cesare
abstract
In several applications involving bilateral telemanipulation, master andslave act at different power scales. In this paper a strategy for passively dealing withvariable communication delay in scaled port-Hamiltonian based telemanipulationover packet switched networks is proposed.
2005
- Approximation of Non--Linear System with Identified Hybrid Models
[Relazione in Atti di Convegno]
S., Simani; Fantuzzi, Cesare
abstract
This paper addresses the identification of non-lineardynamic systems. A wide class of these systems canbe described using non-linear time-invariantregression models, that can be approximated by means of piecewise affine prototypes with an arbitrary degree of accuracy. This workconcerns the identification of piecewise affine model structure through input-output data acquired from a dynamic process. In order to show the effectiveness of the developed technique, the results obtained in the identification of both a simple simulated system and a real dynamic process are reported
2005
- Inheritance of Behavior in Object-Oriented Designs for industrial control systems
[Relazione in Atti di Convegno]
Bonfe', M.; Fantuzzi, Cesare; Secchi, Cristian
abstract
The paper presents a feasible approach to introduce object-orientedtechniques in the industrial practice of control design. The approach is based onthe use of a domain-specific extension of the modeling language UML and on theformalization of design models as transition systems for verification purposes. Inparticular, the paper shows how to exploit model checking techniques to verifythat object classes, designed as subtypes, correctly inherit the behavior of theirbase classes, according to a notion of substitutability specifically defined for theproposed semantics of object-oriented models.
2005
- Object-oriented modeling of logic control systems for industrial applications
[Articolo su rivista]
M., Bonfe'; Fantuzzi, Cesare; Magnani, M.
abstract
The paper presents the results of an application ofobject-oriented modeling techniques to design manufacturing systemslogic controllers. In particular,the semantical aspects ofspecification languages like UML and Statecharts,widely used in manySoftware Engineering methods, are analysed and discussed,with regardto their adequacy for the industrial domain and their verificationwith formal methods.The paper ends with the description of a practicalcase of study, which shows that the proposed design and verificationtechniques can be successfully adopted in a real industrial framework,given domain-specific adaptation of object-oriented modelinglanguages
2005
- Object-oriented modeling of multi-domain systems
[Relazione in Atti di Convegno]
M., Bonfe'; Fantuzzi, Cesare; Secchi, Cristian
abstract
The paper describes a modeling language that aims to provide a unified framework for multi-domain physical systems coupled with computer-based control devices. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows to describe both control software and physical components using the same basic concepts, particularly those of classes and interface ports.
2005
- On the use of UML for modeling physical system
[Relazione in Atti di Convegno]
Secchi, Cristian; Fantuzzi, Cesare; Bonfe', M.
abstract
The aim of this paper is to provide a unified language for modeling both control software and physical plants in real time control systems. This is done by embedding the bond graph modeling language for physical systems into the UML-RT framework, widely used to model distributed real-time software
2005
- Power Scaling in port-Hamiltonian based Telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S.; Fantuzzi, Cesare
abstract
In several applications involving bilateral telemanipulation, master and slave robots act at different power scales (e.g. telesurgery). The aim of this paper is to embed power scaling into port-Hamiltonian based bilateral telemanipulation schemes, In order to deal with nonnegligible transmission delays we propose a novel scattering based communication strategy to properly scale the power exchanged by master and slave while preserving a stable behavior of the overall scheme.
2005
- Sampled data systems passivity and discrete port-Hamiltonian systems
[Articolo su rivista]
S., Stramigioli; Secchi, Cristian; AJ Van der, Schaft; Fantuzzi, Cesare
abstract
In this paper, we present a novel way to approach the interconnection of a continuous and a discrete time physical system first presented in [1]-[3]. This is done in a way which preserves passivity of the coupled system independently of the sampling time T. This strategy can be used both in the field of telemanipulation, for the implementation of a passive master/slave system on a digital transmission line with varying time delays and possible loss of packets (e.g., the Internet), and in the field of haptics, where the virtual environment should 'feel' like a physical equivalent system.
2005
- The problem of packets loss in scaled digital port-Hamiltonian based bilateral telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S.; Fantuzzi, Cesare
abstract
The goal of this paper is to embed power scaling into port-Hamiltonian based telemanipulation schemes over packet switched networks. We propose a discrete scattering based communication strategy and a way to handle lost packets that allow power scaling while preserving a stable behavior of the system independently of any communication delay and of any possible loss of packets
2005
- Transparency in port-Hamiltonian based Telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S.; Fantuzzi, Cesare
abstract
After stability, transparency is the major issue in the design of a telemanipulation system. In this paper we exploit a behavioral approach in order to provide an index for the evaluation of transparency in port-Hamiltonian based teleoperators. Furthermore we provide a transparency analysis of packet switching scattering based communication channels.
2005
- UML come linguaggio di modellazione unificato per sistemi meccatronici
[Relazione in Atti di Convegno]
Bonfe', M.; Fantuzzi, Cesare; Secchi, Cristian
abstract
Nel presente articolo, viene proposto un linguaggio di modellazione il cui scopo è quello di fornire una lingua franca per tutti i progettisti coinvolti nello sviluppo di un sistema meccatronico. Al fine di raggiungere tale obiettivo, il linguaggio presentato unifica i concetti fondamentali dell’approccio orientato agli oggetti (Object-Oriented, O-O), tipico dei sistemi software rappresentati con modelli UML, ed i concetti fondamentali dei Bond Graphs, un linguaggio di modellazione per sistemi fisici di natura eterogenea basato sulle interazioni energetiche fra componenti basilari.L’articolo mostra come i concetti propri dei Bond Graphs ed, in particolare, della loro formalizzazione in termini di sistemi Port-Hamiltonian, possano essere incorporati nel linguaggio UML, adottandone il profilo definito originariamente per sistemi software distribuiti e Real-Time. In tal modo, sia le specifiche strutturali e di comportamento del software di controllo che le dinamiche continue del sistema fisico possono essere descritte in un unico modello, facilitando così la progettazione integrata dei sistemi meccatronici.
2005
- Unified Modeling and Verification of Logic Controllers for Physical Systems
[Relazione in Atti di Convegno]
Bonfe', M.; Fantuzzi, Cesare; Secchi, Cristian
abstract
The paper describes a modeling approach that aims to provide a unified framework for the specification and verification of logic controllers for multi-domain physical systems. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows to describe both control software and physical components using the same basic concepts, like classes and interface ports, and the same modeling notation, based on the UML language. Thanks to this unified approach, it is possible to describe structural and behavioral aspects of any multi-domain system coupled with a logic control device. Moreover, the behavior of the closed-loop system can be analyzed with formal verification techniques for hybrid systems, in order to prove correctness properties otherwise difficult to verify considering only discrete-event models.
2005
- Unified modeling of control software and physical plants
[Relazione in Atti di Convegno]
Secchi, Cristian; Fantuzzi, Cesare; Bonfe', M.
abstract
The aim of this paper is to provide a unified language for modeling bothcontrol software and physical plants in real time control systems. This is done byembedding the bond graph modeling language for physical systems into the UMLRTframework, widely used to model distributed real-time software.
2005
- Verification of Behavioral Substitutability in Object-oriented Models for Industrial Controllers
[Relazione in Atti di Convegno]
Bonfe', M.; Fantuzzi, Cesare; Secchi, Cristian
abstract
The aim of the paper is to provide a practical method to introduce design principles typical of the object-oriented approach, like “design by extension”, to the application domain of manufacturing systems control design. The proposed method is based on a domain-specific extension of the modeling language UML and on the formalization of design models as transition systems for verification purposes. Object-oriented models, formalized according to the proposed semantics, can be analyzed with model checking techniques in order to verify the behavioral conformity of object classes, according to a notion of substitutability which is defined in the paper specifically for the proposed modeling language.
2004
- A practical approach to object-oriented modeling of logic control systems for industrial applications
[Relazione in Atti di Convegno]
M., Bonfè; Fantuzzi, Cesare
abstract
The paper presents the results of an applicationof object-oriented modeling techniques to design manufacturingsystems logic controllers. In particular, the semanticalaspects of specification languages like UML and Statecharts,widely used in many Software Engineering methods, areanalysed and discussed, with regard to their adequacy forthe industrial domain and their verification with formalmethods. The paper ends with the description of a practicalcase of study, which shows that the proposed design andverification techniques can be successfully adopted in a realindustrial framework, given domain-specific adaptation ofobject-oriented modeling languages.
2004
- Application of object-oriented modeling tools to design the logic control system of a packaging machine
[Relazione in Atti di Convegno]
M., Bonfè; Fantuzzi, Cesare
abstract
The paper presents the results of an application of object-oriented modeling techniques to design manufacturing systems logic controllers. In particular, the semantical aspects of specification languages like UML and Statecharts, widely used in many Software Engineering methods, are analysed and discussed, with regard to their adequacy for the industrial domain and their verification with formal methods. The paper ends with the description of a practical case of study, which shows that the proposed design and verification techniques can be successfully adopted in a real industrial framework, given domain-specific adaptation of object-oriented modeling languages.
2004
- Energetic Approach to Parametric Fault detection and Isolation
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; Secchi, Cristian
abstract
This paper concerned with the diagnosis and identification of parametric fault which may occur in a physical system. The method uses a bond graph system model to generate residual signals for fault diagnosis. Fault identification of system parameters is obtained by the analysis of the bond graph model topology.
2004
- On the suitability of object-oriented models for industrial logic controllers
[Relazione in Atti di Convegno]
Bonte, M.; Fantuzzi, C.
abstract
The paper presents a discussion on the practical issues of applying object-oriented modeling and formal verification techniques to the design of Manufacturing Systems logic controllers. In particular, the semantical aspects of specification languages like UML and Statecharts. which are widely used in many areas of Software Engineering, are analysed in terms of their adequacy for the industrial domain Then, the paper presents the results of an application of these modeling languages to a practical case, showing that model checking techniques can also be adopted, given an adequate and domain-speciSc semantics of the object-oriented design model.
2003
- A Variable Structure Approach to Energy Shaping
[Relazione in Atti di Convegno]
Macchelli, A.; Melchiorri, C.; Secchi, Cristian; Fantuzzi, Cesare
abstract
The port-Hamiltonian formalism is a very powerful tool for describingdynamical systems and their interconnections and fordesigning control laws with specified energetic properties. Inthis paper, in particular, it is shown how a variable structurecontrol can be designed in this general framework in order toachieve a passive systems with, additionally, the robust propertiesobtainable with variable structure systems. Simulationresults obtained with a 2-dof manipulator are reported and discussedin order to validate the proposed approach.
2003
- Control of an Industrial Robot Using RTAI Linux
[Relazione in Atti di Convegno]
Secchi, Cristian; Fantuzzi, Cesare; Gianotti, A.
abstract
In this paper we present the real-time control of an industrial manipulator with RTAI-Linux whichhas been developed at the Mechatronics laboratory of the University of Modena and Reggio Emilia. Therobot is an AXTRON and it is produced by the RRRobotica in Reggio Emilia (Italy). The manipulatoris a SCARA-like robot with three degrees of freedom; it has two actuated rotational joints and a manualprismatic joint. The robot is mainly used for micro percussion marking, engraving and glue dispensing.Each rotational joint is actuated by a stepper motor with a resolution of 0.024 mm and the actuated axesare provided with range-delimiters.
2003
- Dealing with Unreliabilities in Digital Passive Geometric Telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S.; Fantuzzi, Cesare
abstract
In this paper two problems arising in the digital passive scheme for telemanipulation presented in are addressed. At first, we show how to preserve system passivity in presence of quantization error introduced by position sensor (i.e. encoders) by introducing energy dissipation. Then, we introduce a scheme for a redundant communication channel that will compensate for missed packets improving performances while preserving passivity of the overall scheme.
2003
- Delayed Virtual Environments: a port-Hamiltonian Approach
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S.; Fantuzzi, Cesare
abstract
In this paper the problem of delayed virtual environments in haptics is addressed. We show that the approach outlined is no longer passive in case of (computational) delay on the output of the virtual environment. Passivity can be recovered using scattering theory; a discretization algorithm which leads to a discrete passive port-Hamiltonian systems with respect to any delay on the output is proposed.
2003
- Design and Verification of Industrial Logic Controllers with UML and Statecharts
[Relazione in Atti di Convegno]
M., Bonfè; Fantuzzi, Cesare
abstract
The paper describes a methodological framework that aims to apply formal design and verification techniques to the domain of Logic Control and Supervision for Manufacturing Systems. The methodology is based on a Object-Oriented approach, supported by a syntactical and semantical adaptation of the semi-formal software specification languages UML and Statecharts. The modeling languages has been subsequently formalized, according to a semantics that take into account the concepts described in the IEC 61131-3 Standard for industrial controllers programming, in order to prove correctness properties expressed in the temporal logic CTL. The verification process is performed by means of the model checking tool SMV.
2003
- Design and Verification of Mechatronic Object-Oriented Models for Industrial Control Systems
[Relazione in Atti di Convegno]
M., Bonfè; Fantuzzi, Cesare
abstract
The paper describes a methodological framework that aims to apply formal design and verification techniques in the development of Industrial Control Systems, with particular regard to the domain of manufacturing machines. The methodology is based on an Object-Oriented approach, revisited in a mechatronic perspective.
2003
- Development of a design pattern methodology for the automotive info-telematic system user interface
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; S., Marzani; R., Montanari; M., Pratesi
abstract
.
2003
- Digital passive geometric telemanipulation
[Relazione in Atti di Convegno]
Secchi, Cristian; Stramigioli, S.; Fantuzzi, Cesare
abstract
In this paper we present an intrinsically passive telemanipulation scheme over a digital transmission line Internet-like. We present an analysis of the energetic behavior of the communication line both in case of loss of packages and in case of variable delay. The sample data nature of the passive controller is explicitly taken into account following the approach outlined
2003
- Il controllo del moto per macchine automatiche
[Monografia/Trattato scientifico]
Canini, G.; Fantuzzi, Cesare
abstract
Motion control for automated machinery
2003
- Model-based Fault Diagnosis in Dynamic Systems Using Identification Techniques
[Monografia/Trattato scientifico]
S., Simani; Fantuzzi, Cesare; Rj, Patton
abstract
Safety in industrial process and production plants is a concern of rising importance, especially if people would be endangered by a catastrophic system failure. On the other hand, because the control devices which are now exploited to improve the overall performance of industrial processes include both sophisticated digital system design techniques and complex hardware (input-output sensors, actuators, components and processing units), there is an increased probability of failure. As a direct consequence of this, control systems must include automatic supervision of closed-loop operation to detect and isolate malfunctions as early as possible. One of the most promising methods for solving this problem is the "analytical redundancy" approach, in which residual signals are obtained. The basic idea consists of using an accurate model of the system to mimic the real process behaviour. If a fault occurs, the residual signal, i.e., the difference between real system and model behaviours, can be used to diagnose and isolate the malfunction. This book focuses on model identification oriented to the analytical approach of fault diagnosis and identification. The problem is treated in all its aspects covering: * choice of model structure; * parameter identification; * residual generation; * fault diagnosis and isolation. Sample case studies are used to demonstrate the application of these techniques. Model-based Fault Diagnosis in Dynamic Systems Using Identification Techniques will be of interest to researchers in control and fault identification. Industrial control engineers interested in applying the latest methods in fault diagnosis will benefit from the practical examples and case studies.
2003
- On the Fault Detection and Isolation of Industrial Robot Manipulators
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; Secchi, Cristian; Visioli, A.
abstract
Fault detection and isolation of robot manipulators is a subject that has beenwidely investigated in the past decade and different methodologies have been proposed.However, there is still a lack of techniques that are adequate to a straightforwardapplication to the detection of real fault in industrial robots. In this paper we proposea very simple but effective strategy for fault detection and isolation, which is based onthe analysis of the robot behavior matching with real mechanical and electrical failures.Simulation results show the effectiveness of the method, despite its straightforwardnesscompared to the approaches proposed by recent literature.
2003
- Parameter identification of piecewise affine dynamic models from input-output data
[Relazione in Atti di Convegno]
Simani, S.; Beghelli, S.; Fantuzzi, C.; Rovatti, R.
abstract
This paper addresses the identification of non-linear dynamic systems. A wide class of these systems can be described using non-linear time-invariant regression models, that can be approximated by means of piecewise affine prototypes with an arbitrary degree of accuracy. This work concerns the identification of piecewise affine model structure through input-output data acquired from a dynamic process. In order to show the effectiveness of the developed technique, the results obtained in the identification of both a simple simulated system and a real dynamic process are reported.
2002
- A Novel Theory for Sample Data Systems
[Relazione in Atti di Convegno]
Stramigioli, S.; Secchi, Cristian; VAN DER SCHAFT, A. J.; Fantuzzi, Cesare
abstract
This paper presents a novel approach to the interconnection of a continuous time and a discrete time physical system. This is done in a way which preserves the passivity of the coupled system independently of the sampling time. A direct application in the field of haptic displays, where a virtual environment should feel like equivalent physical systems, is presented.
2002
- An Application of Software Design Methods to Manufacturing Systems Supervision and Control
[Relazione in Atti di Convegno]
M., Bonfè; C., Donati; Fantuzzi, Cesare
abstract
This paper reports the application of software engineering techniques to the analysis and design of logic and supervision control software for a complex manufacturing system, with particular regard to PLC-based control architectures. The design methodology presented in the paper relies on a mechatronic approach to the modularization of the whole problem, so that an efficient system decomposition can be performed, in order to reduce complexity of the software development task and increase flexibility and maintainability of the application. Modeling concepts derived from both object-oriented and structured analysis methods have been used to describe system modules and behaviour. However, some adaptations have been introduced, because the peculiarities of the manufacturing systems domain were difficult to express within an existing software design method. A practical case of study for the application of the design methodology proposed show that software engineering techniques can be applied successfully even in the unusual field of PLC-based control of manufacturing systems.
2002
- Identification and fault diagnosis of nonlinear dynamic processes using hybrid models
[Relazione in Atti di Convegno]
Simani, S.; Fantuzzi, C.; Beghelli, S.
abstract
This work addresses a novel approach for fault diagnosis of industrial processes using hybrid models. A nonlinear dynamic process can, in fact, be described as a composition of different affine submodels selected according to the process operating conditions. This paper concerns the identification of hybrid model parameters through input-output data affected by additive noise. The fault detection scheme adopted to generate residuals uses the estimated hybrid model. In order to show the effectiveness of the developed technique, the results obtained in the fault diagnosis of a real industrial plant are reported.
2002
- Identification of piecewise affine models in noisy environment
[Articolo su rivista]
Fantuzzi, Cesare; S., Simani; S., Beghelli; R., Rovatti
abstract
This paper addresses the identification of non-linear systems. A wide class of these systems can be described using nonlinear time-invariant regression models, that can be approximated by means of piecewise affine prototypes with an arbitrary degree of accuracy. This work concerns the identification of piecewise affine model parameters through input-output data affected by additive noise. In order to show the effectiveness of the developed technique, the results obtained in the identification of both a simple simulated system and a real dynamic process are reported.
2002
- Neural networks for fault diagnosis and identification of industrial processes
[Relazione in Atti di Convegno]
S., Simani; Fantuzzi, Cesare
abstract
In this work a model--based procedure exploiting analytical redundancy via state estimation techniques for the diagnosis of faults regarding sensors of a dynamic system is presented. Fault detection is based on Kalman filters designed in stochastic environment. Fault identification is therefore performed by means of different neural network architectures. In particular, neural networks are used as function approximators for estimating sensor fault sizes. The proposed fault diagnosis and identification tool is tested on a industrial gas turbine.
2002
- Parametric Identification for Robust Fault Detection
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; S., Simani
abstract
The work presents some simulation results concerning the application of robust model–based fault diagnosis to an industrial process by using identification and disturbance de–coupling techniques. The first step of the considered approach identifies several equation error models by means of the input–output data acquired from the monitored system. Each model describes the different working conditions of the plant. In particular, the equation error term of the identified models takes into account disturbances (non–measurable inputs), non–linear and time–invariant terms, measurement errors, etc. The next step of this method exploits state–space realization of the input–output equation error models allowing to define several equivalent disturbance distribution matrices related to the error terms. Moreover, in order to achieve good robustness properties for a process normally working at different operating points, a single optimal equivalent disturbance distribution matrix is selected. Finally, eigenstructure assignment method for robust residual generation and disturbance de–coupling can be successfully exploited for the fault diagnosis of the dynamic process. The fault diagnosis procedure is applied to a benchmark simulation of a gas turbine process.
2002
- Variable Structure PID Based Visual Servoing for Robotic Tracking and Manipulation
[Relazione in Atti di Convegno]
M., Bonfè; E., Mainardi; Fantuzzi, Cesare
abstract
This paper presents a practical experiment on the use of visual servoing for robotic tracking and manipulation of objects moving on a plane. In this work, the image is acquired from the camera mounted on the end-effector of a 6 DOF industrial robot, and processed on a standard PC-based vision system in order to close the visual servoing loop with a PID based controller. The PID has been implemented with a variable structure, modified according to the estimated velocity of the target, in order to achieve a good step response and to eliminate steady-state error with a moving target. The possibility to perform a stable tracking and to estimate the target dynamics allows also to grasp the object with a prediction based trajectory planning.
2001
- Automatic tuning of myoelectric prostheses
[Articolo su rivista]
C., Bonivento; A., Davalli; Fantuzzi, Cesare; S., Terenzi
abstract
In this paper a software package that uses a Fuzzy Logic Expert System (FLES) to compute myoelectric prosthesis control parameter values is presented and the experimental results from its preliminary practical application are discussed. The prosthesis system is the INAIL artificial arm powered by an electrical motor controlled by a microprocessor using myoelectric signals acquired from skin-surface electrodes placed on the patient muscle stump. The software package here presented, named MCA (Microprocessor Controlled Arm) Auto Tuning, is a software tool for a step-by-step controller parameters tuning procedure, useful for expert operators as well as unskilled amputee patients. The control parameters set-up and subsequent recurrent adjustment are necessary for the prosthesis correct working. These tasks are usually performed by skilled operator together with the patient in the prosthesis-maker laboratory, however this is quite unpractical and involves technicians' waste of time and patients' uneasiness. The MCA Auto Tuning package embodies technician expertize in control parameters set-up in a FLES module. The unskilled patient interacts with the graphical interface of the software, and is guided by the programme to tune the controller parameters in a step-by-step procedure that emulates the traditional expert-aided tuning procedure. The adoption of this program on a large scale may yield considerable economic benefits and improve the service quality supplied to the prosthesis users. In fact the time required to set the prosthesis parameters is remarkably reduced and, consequently, working time of technicians is reduced too, decreasing costs of prostheses makers and providers. Moreover, by using MCA Auto Tuning package the present troubles and outlays for the patient can be dramatically lowered since any artificial arm resetting requires only a few easy adjustment staying at home
2001
- Fuzzy system identification and fault diagnosis of industrial processes
[Relazione in Atti di Convegno]
Simani, S.; Fantuzzi, C.; Beghelli, S.
abstract
This paper proposes a method for fault diagnosis of dynamic processes using the multiple model approach. The technique presented concerns the identification of a non-linear dynamic system based on Takagi-Sugeno (TS) fuzzy models. It can be shown that any non-linear dynamic process can, in fact, be described as a composition of several TS models selected according to process operating conditions. In particular, this work addresses a method for the identification and the optimal selection of the local TS models from a sequence of noisy input-output data acquired from the process. The diagnostic scheme exploits the TS fuzzy models to generate residuals. The developed technique was applied to the fault diagnosis of the input-output sensors of an industrial gas turbine and the results are also presented.
2001
- La sensorizzazione ed il biofeedback nelle protesi di arto superiore
[Relazione in Atti di Convegno]
A., Davalli; R., Sacchetti; Fantuzzi, Cesare
abstract
2001
- Object--Oriented approach to PLC software design for a manufacture machinery using IEC 61131-3 Norm Languages
[Relazione in Atti di Convegno]
M., Bonfè; Fantuzzi, Cesare
abstract
Presents an application of object-oriented methodology to the development of programmable logic controller (PLC) programs. The PLC is widely used as a computer controller of manufacturing machinery, principally because of its robustness and programming simplicity. The IEC 61131-3 norm has been introduced aiming to provide standard languages and structure to the development environments of PLC programs, that up to now have been strictly bound to proprietary languages. Following the IEC 61131-3 prescription, is it also possible to develop well structured, object-oriented control software, which was hardly possible with the former vendor-specific low-level languages. The paper describes an application of the IEC 61131-3 standard to the development of the control software of a medium complexity manufacturing machinery. The software development methodology is reported and comparison regarding development time, software re-usability and application structuring, is then discussed
2001
- Parameter identification for eigenstructure assignment in robust fault detection
[Relazione in Atti di Convegno]
Fantuzzi, C.; Simani, S.; Beghelli, S.
abstract
The paper presents some results on parametric identification of linear systems applied to robust Fault Diagnosis schemes. In our approach, an equation error model is derived from input- output data. In particular, the error term takes into account disturbances (non measurable inputs), nonlinear and time-variant terms, measurement errors, etc. In this manner, state-space realization of the equation error model leads to define a disturbance distribution matrix related to the error term, and, thus, well-known eigenstructure assignment results for robust fault detection can be successfully applied. The proposed procedure has been tested on a industrial gas turbine prototype model in which a sensor fault is simulated. Results from this simulation campaign are also reported.
2001
- PLC object-oriented programming using IEC61131-3 norm languages: An application to manufacture machinery
[Relazione in Atti di Convegno]
Bonfe', M.; Fantuzzi, C.; Poretti, L.
abstract
This paper presents an application of object-oriented methodology to the development of Programmable Logic Controller (PLC) programs. PLC is widely used as computer controller of manufacturing machinery, principally because its robustness and programming simplicity. During the last years, IEC61131-3 norm has been introduced aiming to provide standard languages and structure to the development environments of PLC programs, that are instead strictly bound up to now to proprietary languages. Following IEC61131-3 prescription, is it also possible to develop well structured, object-oriented control software, which was hardly possible with the former vendor-specific low-level languages. This paper describes an application of the novel standard IEC61131-3 to the development of the control software of a medium complexity manufacturing machinery. Software development methodology is reported and comparison regarding development time, software re-usability and application structuring, is then discussed.
2001
- Robotic manipulation experiments through visual feedback
[Relazione in Atti di Convegno]
D., Vigorelli; M., Bonfè; Fantuzzi, Cesare
abstract
This paper presents an experimental study on the use of visual servoing for dexterous robotic manipulation. In the first step of the work, a mathematical model of the whole system has been derived, then a non – linear PID regulator with Smith predictorstructure has been developed. The feedback signal for the controller comes directly from the visual sensor. Some experiments on following with robot end-effector a moving target have been performed, showing efficiency of the control system.This work on visual feedback differs from other similar experiments mainly because the inner architecture of the robotcontroller is assumed unknown, i.e. the inner control loop of the robot has not been modified.
2001
- Robust Fault Diagnosis of Dynamic Processes using Parametric Identification with Eigenstructure Assignment Approach
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; S., Simani; S., Beghelli
abstract
Presents some results concerning robust fault diagnosis of dynamic processes using a parametric identification technique. The first step of the considered approach estimates an equation error model by means of the input-output data acquired from the monitored system. In particular, the equation error term of the model takes into account disturbances, non-linear and time-variant terms, measurement errors, etc. The next step of the method requires a state-space realization of the input-output equation error model which allows us to define an equivalent disturbance distribution matrix related to the error term. Therefore, the eigenstructure assignment results for robust fault diagnosis can be successfully applied. The proposed procedure has been tested by means of a industrial process simulator. In such a manner, sensor, component and actuator faults can be simulated on an single shaft gas turbine. Results from this simulator are also reported
2001
- Tuning of myoelectric prostheses using fuzzy logic
[Articolo su rivista]
Bonivento, C.; Davalli, A.; Fantuzzi, C.
abstract
This contribution concerns the use of a supervisory expert system based on fuzzy logic for the parameter adjusting of myoelectric prostheses. The prosthesis system is an artificial arm produced by INAIL in Vigorso (Bologna, Italy), which is equipped with an on-board actuation system. The expert system guides patients through an interactive session whose aim is to test the prosthesis functionality and, when necessary, to self-adjust the parameters.
2000
- Diagnosis techniques for sensor faults of industrial processes
[Articolo su rivista]
Silvio, Simani; Fantuzzi, Cesare; Sergio, Beghelli
abstract
In this paper a model-based procedure exploitinganalytical redundancy for the detection and isolation of faults ininput--output control sensors of a dynamic system is presented.The diagnosis system is based on state estimators, namely dynamicobservers or Kalman filters designed in deterministic and stochasticenvironment respectively, and uses residual analysis and statisticaltests for fault detection and isolation.The state estimators are obtained from input--output data process andstandard identification techniques based on ARX orerrors--in--variables models, depending on signal to noise ratio. Inthe latter case the Kalman filter parameters, i.e. the modelparameters and the input--output noise variances, are obtained byprocessing the noisy data according to the Frisch scheme rules. The proposed fault detection and isolation tool has been tested on a single--shaft industrial gas turbine model. Results from simulation show that minimum detectable faults are perfectly compatible with the industrial target of this application.
2000
- Fault diagnosis in power plant using neural networks
[Articolo su rivista]
Simani, S.; Fantuzzi, Cesare
abstract
Fault diagnosis and identification (FDI) have been widely developed during recent years. Model--based methods, fault tree approaches and pattern recognition techniques are among the most common methodologies used in such tasks. Neural networks have been used in FDI problems for model approximation and pattern recognition as well. However, because difficulties to perform Neural Network training on dynamic patterns, the second approach seems more adequate. In this paper, the FDI methodology consist of two stages. In the first stage, the fault is detected on the basis of residuals generated from a bank of Kalman filters, while, in the second stage, fault identification is obtained from pattern recognition techinques implemented by Neural Networks. The proposed fault diagnosis tool has been tested on a model of a power plant and results from simulations are reported and commented in the paper.
2000
- High speed DSP-based implementation of piecewise-affine and piecewise-quadratic fuzzy systems
[Articolo su rivista]
R., Rovatti; Fantuzzi, Cesare; S., Simani
abstract
The paper tackles the problem of executing high-dimensional fuzzy inferences following zeroth- and first-order Takagi–Sugeno inference models. The choice of a proper AND operator, which is compatible with all the semantic requirements for a conjunctive aggregation, results in an input–output relationship which is piecewise affine or quadratic. The proposed inference procedures exploit this to perform the computation from inputs to output in a time that does not grow exponentially with the number of inputs. Some details of the implementation of the two inference procedures on a TMS320C6201 are given along with some simulation results demonstrating the effectiveness of the piecewise approach.
2000
- Mechatronic objects encapsulation in IEC 1131-3 norm
[Relazione in Atti di Convegno]
Bonfe, Marcello; Fantuzzi, Cesare
abstract
This paper concerns with the definition and use of 'mechatronic objects' for the design of complex manufacturing system as large machinery. In particular the programming languages and structures defined under the IEC 1131-3 norm are considered regarding the software encapsulation of the mechanical system. The paper reports about a real application example of the proposed concepts showing effectiveness of the object-oriented framework for industrial applications.
2000
- Nonlinear dynamic system modelling in noisy environment using multiple model approach
[Relazione in Atti di Convegno]
S., Simani; Fantuzzi, Cesare; R., Rovatti; S., Beghelli
abstract
A nonlinear dynamic process can be described as a composition of several local affine models selected according to the process operating conditions. Such a compound system requires the identification of the local models from data. This work addresses a method for the identification and the optimal selection of the local affine models from a sequence of noisy measurements acquired from the process. The developed technique is applied to the identification of a simulated model
1999
- Nonlinear algebraic system identification via piecewise affine models in stochastic environment
[Relazione in Atti di Convegno]
S., Simani; Fantuzzi, Cesare; R., Rovatti; S., Beghelli
abstract
This paper discusses the issue of nonlinear system modelling by means of continuous piecewise affine models identified from noisy data. Based on the assumption that a piecewise affine system can approximate with arbitrary degree of accuracy any nonlinear relation, the identification problem is formulated within the Frisch scheme. This identification procedure is well established for affine systems and here modified and improved to be applied to piecewise affine system identification. The simulation results of a test case (the identification of a continuous piecewise affine function) shows that an effective identification method has been achieved.
1999
- Parameter identification for piecewise affine fuzzy models in noisy environment
[Articolo su rivista]
Silvio, Simani; Fantuzzi, Cesare; Riccardo, Rovatti; Sergio, Beghelli
abstract
In this paper the problem of identifying a fuzzy model from noisy data is addressed. The piece-wise affine fuzzy model structure is used as non linear prototype for a multi--input, single--output unknown system. The consequents of the fuzzy model are identified from noisy data which are collected from experiments on the real system. The identification procedure is formulated within the Frisch scheme, well established for linear systems, which is extended so that it applies to piecewise-affine, constrained models
1998
- Application of a neural network in gas turbine control sensor fault detection
[Relazione in Atti di Convegno]
Simani, S.; Fantuzzi, C.; Spina, P. R.
abstract
In this paper an application of a procedure using a neural network for the detection and isolation of faults modeled by step functions in input-output control sensors of a single shaft industrial gas turbine is presented. The real process is modeled as a linear dynamic system corrupted by stochastic additive noise. The diagnosis system involves dynamic observers and utilizes the neural network in order to classify observer residuals into fault classes.
1998
- Fault detection and isolation based on dynamic observers applied to gas turbine control sensors
[Relazione in Atti di Convegno]
Simani, S.; Spina, P. R.; Beghelli, S.; Bettocchi, R.; Fantuzzi, C.
abstract
In order to prevent machine malfunctions and to determine the machine operating state, it is necessary to use correct measurements from actual system inputs and outputs. This requires the use of techniques for the detection and isolation of sensor faults. In this paper an approach based on analytical redundancy which uses dynamic observers is suggested to solve the sensor faxilt detection and isolation problem for a single-shaft industrial gas turbine. The proposed technique requires the generation of classical residual functions obtained with different observer configurations. The diagnosis is performed by checking fluctuations of these residuals caused by faults.
1998
- Fault detection and isolation based on dynamic observers applied to gas turbine control sensors
[Relazione in Atti di Convegno]
Simani, S.; Spina, P. R.; Beghelli, S.; Bettocchi, R.; Fantuzzi, C.
abstract
In order to prevent machine malfunctions and to determine the machine operating state, it is necessary to use correct measurements from actual system inputs and outputs. This requires the use of techniques for the detection and isolation of sensor faults. In this paper an approach based on analytical redundancy which uses dynamic observers is suggested to solve the sensor fault detection and isolation problem for a single-shaft industrial gas turbine. The proposed technique requires the generation of classical residual functions obtained with different observer configurations. The diagnosis is performed by checking fluctuations of these residuals caused by faults.
1998
- Multiple-layer variable structure controller with parameter adaptation.
[Articolo su rivista]
C., Bonivento; Fantuzzi, Cesare
abstract
This paper deals with the design procedure of aMultiple Layer Variable Structure Controller (ML-VSC) with on-lineparameter adaptation.The ML-VSC is obtained by non-linear interpolation of the control lawsof a set of VSC with sliding mode dynamics, each of them designed onthe basis of progressively pessimistic estimates of the parametricuncertainty and disturbance input of the plant.This new structure improves both the robustness and controlperformance of the single VS controller when poor knowledge on plantparameters and disturbance bounds is available.The control algorithm is completed by an on-line adaptation mechanismaiming to achieve fine tuning of the parameters. This mechanism isbased on the trade-off between the ``chattering'' effect and thetracking error. This heuristics, formulated in terms of ``if--then''linguistic rules, is implemented by a Fuzzy Logic (FL) algorithm.The paper also addresses the stability issue of the closed loopsystem, giving sufficient conditions for global stability in thepresence of bounded disturbance and modeling uncertainties. Finally, asimple simulation example illustrates the main design steps of thecontrol approach proposed
1998
- Noise rejection in parameters identification for piecewise linear fuzzy models
[Relazione in Atti di Convegno]
Simani, S.; Fantuzzi, C.; Rovatti, R.; Beghelli, S.
abstract
The fuzzy model identification problem from noisy data is addressed. The piecewise linear fuzzy model structure is used as a nonlinear prototype for a multi-input, single-output unknown system. The consequent of the fuzzy model is identified using noisy data, e.g. collected from experiments on a real system. The identification procedure is formulated within the Frisch scheme, well established for linear systems, which has been modified and improved to be applied in fuzzy systems field.
1998
- Parameters identification for piecewise linear models with weakly varying noise.
[Relazione in Atti di Convegno]
R., Rovatti; Fantuzzi, Cesare; S., Simani; S., Beghelli
abstract
This paper concerns the identification problem of piece–wise linear models from noisy data. The piece–wise linear models are of interest because they can approximate with arbitrary degree of accuracy any non–linear model, holding mathematical tractability and generality. The identification procedure is formulated within the Frisch scheme, well established for linear systems, which has been modified and improved to be applied for piece–wise linear systems. Further, using reasonable hypothesis on the data noise, the identification procedure is enhanced with respect to the linear case.
1998
- Quantized norms and generalized relational composition on dense universes
[Articolo su rivista]
Riccardo, Rovatti; Fantuzzi, Cesare
abstract
Decision-making procedure based on fuzzy relational composition mayrequire that the involved connectives are not idempotent tohandle significant information properly. Yet, non-idempotence mayresult in meaningless inference when the universes of discourse aredense. Here we propose a novel kind of connective and a formaldefinition of relational composition for dense universes of discoursewhich allow the aggregation of different path of reasoning confirmingeach other without incurring in total loss of information
1998
- Supervisory system of myoelectric prostheses
[Relazione in Atti di Convegno]
Bonivento, C.; Fantuzzi, C.
abstract
This paper concerns with the use of a supervisory expert system to parameter adjusting of myoelectric prostheses. The prosthesis system is an artificial arm produced by INAIL in Vigorso (Bologna, Italy), which is equipped by on-board actuation system. The expert system, which is developed using a fuzzy logic algorithm, guides the patients through an interactive session aiming to test the prosthesis functionality and, when necessary, to self-adjust the parameters. The prosthesis control system is connected through a RS232 communication link to a Personal Computer running the expert system. A teleconference service is included in the package, which permits the technicians to monitor remotely the tuning session. The paper presents the overall characteristics of auto-tuning system, detailing particularly the fuzzy logic algorithm which is the core of the expert system. Some preliminary experimental results on the application of the system to patients are reported as well.
1997
- Efficient Least Squares Identification with SISO Takagi--Sugeno Models
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; R., Rovatti
abstract
In this paper we exploit the approximation capabilities of Takagi-Sugeno models to devise an identification procedure for Single-Input Single-Output systems, which minimizes the squared error between the model and the target. The adoption of a model featuring an increased locality allows a substantial reduction in the complexity of the identification phase in which samples are taken into account. Then, a data-independent mapping is devised to translate modified Takagi-Sugeno models into conventional ones.
1997
- Fuzzy logic control of a variable displacement hydraulic pump.
[Capitolo/Saggio]
C., Bonivento; M., Ruggeri; Fantuzzi, Cesare; R., Paoluzzi
abstract
The control of electrohydraulic systems is a very challenging problem because of a variety of saturations and other non-linear effects. The present chapter aims to define a viable solution to this control problem properly using fuzzy logic techniques. The testbed system is a variable-displacement axial piston pump used in an hydro-mechanical circuit applied to earth moving machinery.
1997
- Fuzzy logic expert system for automatic tuning of myoelectric prostheses
[Relazione in Atti di Convegno]
Bonivento, C.; Davalli, A.; Fantuzzi, C.; Terenzi, S.
abstract
The paper presents a software package for automatic tuning of control parameters of myoelectric prosthesis. The prosthesis system is the INAIL artificial arm controlled by a microprocessor using myoelectric signals acquired from skin-surface electrodes placed on the patient muscle stump. Usually, qualified staff is necessary for control parameters set-up and subsequent recurrent adjustments, and therefore patients are forced to come back frequently at prosthesis factory laboratories. The proposed software interacts with unskilled patients and automatically set up the control parameters of the prosthesis using qualified staff knowledge stored in a Fuzzy Logic Expert System (FLES). In this paper the software package is presented and some preliminary results from its application are discussed.
1997
- Hybrid limitator of speed-couple (EHL) for variable capacity pumps
[Articolo su rivista]
Paoluzzi, R.; Zarotti, G. L.; Ruggeri, M.; Fantuzzi, C.
abstract
To optimise the performance of thermic engines independently of the load is a very difficult problem. In open cycle application for mobile use variable capacity pumps with control of various kinds can solve the problem to a certain degree but difficulties in the power control will remain. A hybrid electrohydraulic control system with couple and speed limitation can solve most of these problems and the use of fuzzy technology makes it very robust.
1997
- Introduction to Fuzzy Logic: Application to Industrial Problems
[Capitolo/Saggio]
Fantuzzi, Cesare
abstract
Introduction to Fuzzy Control
1997
- Q-norms and Generalized Relational Composition on Dense Universes
[Relazione in Atti di Convegno]
R., Rovatti; Fantuzzi, Cesare
abstract
Q-norms and generalized relational composition on dense universes
1997
- Rule Reduction Algorithm for SISO Takagi-Sugeno Models
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; R., Rovatti
abstract
Rule Reduction Algorithm for SISO Takagi-Sugeno Models
1996
- Electronic hybrid limiter (EHL) for pump displacement
[Capitolo/Saggio]
Paoluzzi, R.; Zarotti, L. G.; Ruggeri, M.; Fantuzzi, C.
abstract
The paper reports upon numerical simulation tests carried out on a variable displacement axial piston pump equipped with multiple automatic controls. The swashplate control circuit includes two classical hydraulic stages with two tandem three way valves (the pressure compensator and the flow limiter) and a servovalve with digital control circuit acting as a hybrid torque or/and speed limiter. The dynamic response of the system is evaluated for both separate and combined control functions. The effect of changes in the digital control circuit is discussed with reference to the system response to various load demands with special emphasis devoted to the benefits induced by the use of fuzzy control logic.
1996
- Hybrid Multiple Control of Pump Displacement
[Relazione in Atti di Convegno]
R., Paoluzzi; L., Zarotti; M., Ruggeri; Fantuzzi, Cesare
abstract
Multiple controls of variable displacement pumps in open-loop applications are widely used. The first stage, common to all applications, is the pressure compensator, and flow and torque or speed compensators (or limiters) can be added as additional stages. The practical implementation of the control circuits is well known and documented in the fully hydromechanical or (more commonly in closed--loop hydrostatic transmissions) in the fully electrohydraulic option. The main concern is referred to the torque or speed limiter used as third stage in hydromechanical control circuits, as both of them show a number of drawbacks in handling the pump interaction on the mechanical side (i.e. interaction with the internal combustion engine). Aim of the paper is to show how an electronically controlled proportional servovalve, together with a properly suited (both traditional and based on fuzzy logic) control strategy featuring both torque and speed limitation, can overcome those limitation to a large extent, and can also be used as an add-on to existing pumps with double (pressure and flow) hydromechanical compensators.
1996
- Improved inference for Takagi--Sugeno models
[Relazione in Atti di Convegno]
R., Babuska; Fantuzzi, Cesare; H., Verbruggen
abstract
Some undesirable properties of the standard Takagi--Sugeno (TS) inference method are discussed in relation to analysis of the TS model and to its approximation accuracy. A new inference method based on a smoothing maximum function is proposed. This method guarantees smoothness of the model output to a desired degree, boundedness of the output gradient at each point by the local gradients of the rule consequents and also improves the accuracy of the TS model, as demonstrated on numerical examples.
1996
- Improved inference for takagi–sugeno models.
[Capitolo/Saggio]
R., Babuška; Fantuzzi, Cesare; H. B., Verbruggen
abstract
Some undesirable properties of the standard Takagi–Sugeno (TS) inference method are discussed in relation to analysis of the TS model and to its approximation accuracy. A new inference method based on a smoothing maximum function is proposed. This method guarantees smoothness of the model output to a desired degree, boundedness of the output gradient at each point by the local gradients of the rule consequents and also improves the accuracy of the TS model, as demonstrated on numerical examples.
1996
- On the Approximation Capabilities of the Homogeneous Takagi-Sugeno Model
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; R., Rovatti
abstract
The approximation capability of the Takagi-Sugeno model are investigated in this paper. This kind of model features a functional consequent which is usually a first-degree polynomial in the inputs. The importance of the constant term in such a polynomial is highlighted showing that if it is discarded the Takagi-Sugeno model features the same approximation power of the simpler constant-consequence systems.
1996
- Showcase of a Fuzzy Logic Controller Design
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; C., Bonivento
abstract
In this paper a method developed by the authors for defining a Sugeno--Takagi Fuzzy Logic Controller parameters is illustrated. The procedure, based on the Variable Structure System approach, defines an adaptive fuzzy control structure. In order to show the effectiveness of the proposed solution, the controller is applied to a known benchmark control problem and the obtained simulation results are discussed.
1996
- S-Norm aggregation of infinite collections
[Articolo su rivista]
R., Rovatti; Fantuzzi, Cesare
abstract
The aggregation of membership values by means of theiterate application of an s-norm is of cardinal relevance for thedevelopment of any general theory of approximate reasoning whichrelies on a {\em sup-t} model for relation composition. Here wepresent a definition of s-norm aggregation for possibly infinitecollections, which can be demonstrated to consistently generalizeprevious approaches. It provides a common framework in which classical{\em sup-t} and finite {\em s-t} compositions can be analyzed as wellas other significant cases. General properties of the s-normaggregation concept, its specialization for the class of continuouss-norms and its relationship with fuzzy measure theory are discussed
1996
- Stability Analysis of Takagi--Sugeno Fuzzy Systems by Lyapunov Method
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; R., Babuska; S., Stramigioli; H., Verbruggen
abstract
Stability analysis of the Takagi--Sugeno fuzzy model via Lyapunov method is discussed in this paper. The fuzzy model is like a non-linear interpolation of linear submodels via state-depending membership functions. For this model we introduce a stability test based on the direct method of Lyapunov that, contrary to other existing methods, considers explicitly the membership functions in the criteria.
1995
- Adaptive Fuzzy Logic Controller Synthesis Via Sliding Mode Approach
[Relazione in Atti di Convegno]
C., Bonivento; Fantuzzi, Cesare; L., Martini
abstract
The VSC (Variable Structure Control) with SM (Sliding Mode) dynamics is a well known theory used to define a robust controller for a plant in the presence of model uncertainty and disturbance input. In this paper a method for defining a Sugeno type of Fuzzy Logic Controller (FLC) parameters, derived from VSC design considerations, is proposed. The idea is to generate a set of VSC controllers, related to different bounds on model uncertainties and disturbances, and use the interpolatory capability of the fuzzy paradigm to merge the VSC behavior in only one structure. Moreover a heuristic algorithm for the on-line FC parameter tuning is given. The global stability of the proposed controller is also demonstrated.Simulations show that the FC obtained performs better than the basic VSC counterpart in the presence of unmodeled dynamics and disturbances.
1995
- Analysis and Synthesis Methods for Fuzzy Logic Controllers
[Monografia/Trattato scientifico]
Fantuzzi, Cesare
abstract
Fuzzy logic in control has been successful used to capture heuristic control laws obtained from human experience or engineering practice in automated algorithm. These control laws are defined by means of linguistic rule, for example ``if the pressure is high, then decrease the pump power''. The heuristic approach in the controller design can be appealing for its simplicity, but formal design method can be mandatory in some cases.This thesis aims at defining some original method for the analysis and design of fuzzy logic controller. More in detail some properties of Variable Structure Control theory have been used, in particular the sliding mode dynamics, to design the rules and the membership functions of a Fuzzy Logic Control. In the second part of the thesis a model-based procedure for the synthesis of a fuzzy logic controller is presented. This algorithm defines the linguistic rules of a fuzzy logic controller, starting from a desired closed loop behavior and a plant model, both described via linguistic statements. To obtain a plant model in a linguistic form, suitable for the above algorithm, a novel identification procedure is proposed.
1995
- Fuzzy Logic--Sliding Mode Hybrid Control
[Relazione in Atti di Convegno]
Fantuzzi, Cesare
abstract
In this paper a hybrid fuzzy logic--sliding mode control technique is presented and discussed. The Variable Structure Control (VSC) with Sliding Mode (SM) dynamic is a well known theory for the design of robust and globally stable controller for non--linear system. In this paper a VSC based design procedure for a fuzzy controller is given, and stability properties are discussed. In order to outline the feature of the proposed idea, the hybrid controller has been tested on a robotic gripper. The experimental results show good performance of the fuzzy controller.
1995
- Template--Base Fuzzy System Modeling
[Relazione in Atti di Convegno]
Fantuzzi, Cesare
abstract
In this paper a template--base algorithm for fuzzy system modeling is presented and discussed. The algorithm identifies the fuzzy rules describing the system behavior from input--output data. This approach assumes an expert has provided a collection of linguistic terms (templates) that describe the fuzzy model environment. The algorithm computes the {\em level of firing} of templates by the input--output data. The best rule candidate is formed by picking up the terms with closer level of firing. In order to show the procedure performance, the identification of algebraic and dynamics systems are reported.
1994
- linguistic Rule Synthesis of a Fuzzy Logic Controller
[Relazione in Atti di Convegno]
Fantuzzi, Cesare
abstract
In this paper a model-based procedure for the synthesis of a fuzzy logic controller is presented. This procedure defines the linguistic rules of a fuzzy logic controller, starting from a desired closed loop behavior and a plant model, both described via linguistic statements. Moreover we introduce a novel identification procedure to obtain a plant model in a linguistic form, suitable for the above algorithm.
1994
- The U. B. Hand II Control system: Design Features and Experimental Results
[Relazione in Atti di Convegno]
Eusebi, A.; Fantuzzi, C.; Melchiorri, C.; Sandri, M.; Tonielli, A.
abstract
In this paper the main features of the control system of the University of Bologna Robotic Hand Version II, its sensory and actuation systems are presented and discussed. The hand, a three fingered articulated hand with high dexterity features, is installed on an anthropomorphic arm, a PUMA 560, and in total the system has 16 degrees of freedom. Details about the overall control system architecture and some preliminary experimental results are given. The control system is based on a multiprocessor hardware platform and multilayer software levels: a Sun Sparcstation for the user interface, a 68030 and DSP boards on VME bus for real-time coordination, a custom DSP-based board located at the forearm level, that ensures the hardware support for real-time force computation and position/torque servo loops for the hand
1993
- Considerations on Fuzzy Control Design Based on Sliding Mode Approach
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; S., Cipolla
abstract
In this paper a method for defying Fuzzy Control parameters from VSC (Variable Structure Control) design considerations is proposed. A relationship between Fuzzy Control and VSC is outlined, and, therefore, a method to define fuzzy parameters from VSC theory is derived. Robustness and stability of the controlled system are implicitly assured by VSC properties.
1992
- A Smart Sensory and Actuation System for the University of Bologna Robotic Hand: Latest Developments and Implementations.
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; C., Rossi; A., Tonielli; G., Vassura
abstract
The control system of the U.B. robotic Hand
1992
- The Control System of the U.B. Hand II: an Overview of the Hardware Design and Implementation
[Relazione in Atti di Convegno]
Fantuzzi, Cesare; A., Tonielli
abstract
The paper describes the control system of the University of Bologna Robotic Hand.